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Bug #6774 » WTreeView.C

Thomas Frank, 11/28/2018 04:32 PM

 
/*
* Copyright (C) 2008 Emweb bvba, Kessel-Lo, Belgium.
*
* See the LICENSE file for terms of use.
*/

#include <math.h>
#include <cmath>
#include <iostream>
#include <boost/algorithm/string.hpp>

#include "Wt/WAbstractItemModel.h"
#include "Wt/WApplication.h"
#include "Wt/WContainerWidget.h"
#include "Wt/WEnvironment.h"
#include "Wt/WItemDelegate.h"
#include "Wt/WItemSelectionModel.h"
#include "Wt/WStringStream.h"
#include "Wt/WTemplate.h"
#include "Wt/WText.h"
#include "Wt/WTheme.h"
#include "Wt/WTreeView.h"
#include "Wt/WVBoxLayout.h"
#include "Wt/WWebWidget.h"

#include "WebUtils.h"

#ifndef WT_DEBUG_JS
#include "js/WTreeView.min.js"
#endif

#include <limits>

#if defined(_MSC_VER) && (_MSC_VER < 1800)
namespace {
double round(double x)
{
return floor(x + 0.5);
}
}
#endif

/*
TODO:

nice to have:
- stateless slot implementations
- keyboard navigation ?
*/

#ifndef DOXYGEN_ONLY

// Widest scrollbar found ? My Gnome Firefox has this
#define SCROLLBAR_WIDTH 22
#define UNKNOWN_VIEWPORT_HEIGHT 30

namespace Wt {

LOGGER("WTreeView");

class ContentsContainer final : public WContainerWidget
{
public:
ContentsContainer(WTreeView *treeView)
: treeView_(treeView)
{
setLayoutSizeAware(true);
}

protected:
virtual void layoutSizeChanged(int width, int height) override
{
treeView_->contentsSizeChanged(width, height);
}

private:
WTreeView *treeView_;
};

class ToggleButtonConfig
{
public:
ToggleButtonConfig(WWidget *parent, const std::string& styleClass)
: styleClass_(styleClass)
{
toggleJS_.reset(new JSlot(parent));
}

void addState(const std::string& className) {
states_.push_back(className);
}

void generate() {
WApplication *app = WApplication::instance();

std::stringstream js;
js <<
"function(s, e) {"
"""var states = new Array(";

for (unsigned i = 0; i < states_.size(); ++i) {
if (i != 0)
js << ',';
js << '\'' << states_[i] << '\'';
}

js <<
"""), i, il;"
"""for (i=0; i<" << states_.size() << "; ++i) {"
"" "if ($(s).hasClass(states[i])) {"
"" << app->javaScriptClass() << ".emit(s, 't-'+states[i]);"
"" "$(s).removeClass(states[i])"
"" ".addClass(states[(i+1) % " << states_.size() << "]);"
"" "break;"
"" "}"
"""}"
"}";
toggleJS_->setJavaScript(js.str());
}

const std::vector<std::string>& states() const { return states_; }
const std::string& styleClass() const { return styleClass_; }

private:
std::vector<std::string> states_;
std::unique_ptr<JSlot> toggleJS_;
std::string styleClass_;

friend class ToggleButton;
};

class ToggleButton : public Wt::WText
{
public:
ToggleButton(ToggleButtonConfig *config)
: config_(config)
{
setStyleClass(config_->styleClass());

setInline(false);

if (WApplication::instance()->environment().ajax()) {
clicked().connect(*config_->toggleJS_);
clicked().preventPropagation();

for (unsigned i = 0; i < config_->states().size(); ++i)
signals_.push_back(cpp14::make_unique<JSignal<>>(this, "t-" + config_->states()[i]));
} else {
clicked().connect(this, &ToggleButton::handleClick);
for (unsigned i = 0; i < config_->states().size(); ++i)
signals_.push_back(cpp14::make_unique<Signal<>>());
}
}

SignalBase& signal(int i) { return *signals_[i]; }

void setState(int i)
{
setStyleClass(config_->styleClass() + config_->states()[i]);
}

private:
std::vector<std::unique_ptr<SignalBase>> signals_;
ToggleButtonConfig *config_;

void handleClick() {
for (unsigned i = 0; i < config_->states().size(); ++i)
if (boost::ends_with(styleClass().toUTF8(), config_->states()[i])) {
(dynamic_cast<Signal<> *>(signals_[i].get()))->emit();
break;
}
}
};

class RowSpacer final : public Wt::WWebWidget
{
public:
RowSpacer(Wt::WTreeViewNode *node, int height)
: node_(node),
height_(0)
{
setHeight(0);
setInline(false);
setStyleClass("Wt-spacer");
}

void setRows(int height, bool force = false);

int rows() const { return height_; }
Wt::WTreeViewNode *node() const { return node_; }

int renderedRow(int lowerBound = 0,
int upperBound = std::numeric_limits<int>::max());

protected:
virtual Wt::DomElementType domElementType() const override
{
return Wt::DomElementType::DIV;
}

private:
Wt::WTreeViewNode *node_;
int height_;
};

class WTreeViewNode : public WContainerWidget
{
public:
WTreeViewNode(WTreeView *view, const WModelIndex& index,
int childrenHeight, bool isLast, WTreeViewNode *parent);
~WTreeViewNode();

void update(int firstColumn, int lastColumn);
void updateGraphics(bool isLast, bool isEmpty);
void insertColumns(int column, int count);
void removeColumns(int column, int count);
bool isLast() const;

void rerenderSpacers();

const WModelIndex& modelIndex() const { return index_; }
int childrenHeight() const { return childrenHeight_; }
int renderedHeight();
bool childrenLoaded() const { return childrenLoaded_; }

WWidget *widgetForModelRow(int row);
WTreeViewNode *nextChildNode(WTreeViewNode *n);

bool isAllSpacer();

void setTopSpacerHeight(int rows);
void addTopSpacerHeight(int rows);
int topSpacerHeight();

void setBottomSpacerHeight(int rows);
void addBottomSpacerHeight(int rows);
int bottomSpacerHeight();

RowSpacer *topSpacer(bool create = false);
RowSpacer *bottomSpacer(bool create = false);

WContainerWidget *childContainer();

void shiftModelIndexes(int start, int count);

WTreeViewNode *parentNode() const { return parentNode_; }

bool isExpanded();

void adjustChildrenHeight(int diff);
void normalizeSpacers();

void selfCheck();

WTreeView *view() const { return view_; }

int renderedRow(int lowerBound = 0,
int upperBound = std::numeric_limits<int>::max());
int renderedRow(WTreeViewNode *node,
int lowerBound = 0,
int upperBound = std::numeric_limits<int>::max());

void renderSelected(bool selected, int column);

void doExpand();
void doCollapse();

WWidget *cellWidget(int column);

private:
WTreeView *view_;
WTemplate *nodeWidget_;
WContainerWidget *childContainer_;
WModelIndex index_;
int childrenHeight_;
WTreeViewNode *parentNode_;
bool childrenLoaded_;
void loadChildren();

WModelIndex childIndex(int column);

void setCellWidget(int column, std::unique_ptr<WWidget> w);
void addColumnStyleClass(int column, WWidget *w);
};

void RowSpacer::setRows(int height, bool force)
{
if (height < 0) {
LOG_ERROR("RowSpacer::setRows() with heigth " << height);
height = 0;
}

if (height == 0)
removeFromParent();
else
if (force || height != height_) {
height_ = height;
setHeight(node_->view()->rowHeight() * height);
}
}

int RowSpacer::renderedRow(int lowerBound, int upperBound)
{
Wt::WTreeViewNode *n = node();

int result = 0;
if (this == n->bottomSpacer())
result = n->childrenHeight() - n->bottomSpacerHeight();

if (result > upperBound)
return result;
else
return result
+ n->renderedRow(lowerBound - result, upperBound - result);
}

WTreeViewNode::WTreeViewNode(WTreeView *view, const WModelIndex& index,
int childrenHeight, bool isLast,
WTreeViewNode *parent)
: view_(view),
nodeWidget_(nullptr),
childContainer_(nullptr),
index_(index),
childrenHeight_(childrenHeight),
parentNode_(parent),
childrenLoaded_(false)
{
nodeWidget_ = addWidget(cpp14::make_unique<WTemplate>
(tr("Wt.WTreeViewNode.template")));
nodeWidget_->setStyleClass("Wt-item");
nodeWidget_->bindEmpty("cols-row");
nodeWidget_->bindEmpty("expand");
nodeWidget_->bindEmpty("no-expand");
nodeWidget_->bindEmpty("col0");

// TF: Although it seems, that this ctor never gets called with childrenheight == -1
// for non-root nodes, the variable 'selfheight' does not make any sense here,
// if not properly initialized *before* its one and only usage below...
int selfHeight = index == view_->rootIndex() ? 0 : 1;
// int selfHeight = 0;
bool needLoad = view_->isExpanded(index_);

if (index_ != view_->rootIndex() && !needLoad)
childContainer()->hide();

if (needLoad) {
childrenLoaded_ = true;
if (childrenHeight_ == -1)
childrenHeight_ = view_->subTreeHeight(index_) - selfHeight;

if (childrenHeight_ > 0)
setTopSpacerHeight(childrenHeight_);
} else
childrenHeight_ = 0;

if (index_ != view_->rootIndex()) {
updateGraphics(isLast, !view_->model()->hasChildren(index_));
insertColumns(0, view_->columnCount());

// TF: Too late for initialization. Variable never referenced again...
// selfHeight = 1;

if (view_->selectionBehavior() == SelectionBehavior::Rows &&
view_->isSelected(index_))
renderSelected(true, 0);
}

view_->addRenderedNode(this);
}

WTreeViewNode::~WTreeViewNode()
{
view_->removeRenderedNode(this);

if (view_->isEditing()) {
WModelIndex parent = index_.parent();

int thisNodeCount = view_->model()->columnCount(parent);

for (int i = 0; i < thisNodeCount; ++i) {
WModelIndex child = childIndex(i);
view_->persistEditor(child);
}
}
}

void WTreeViewNode::update(int firstColumn, int lastColumn)
{
WModelIndex parent = index_.parent();

int thisNodeCount = view_->model()->columnCount(parent);

for (int i = firstColumn; i <= lastColumn; ++i) {
WModelIndex child = i < thisNodeCount ? childIndex(i) : WModelIndex();

WWidget *w = cellWidget(i);

WFlags<ViewItemRenderFlag> renderFlags = None;
if (view_->selectionBehavior() == SelectionBehavior::Items &&
view_->isSelected(child))
renderFlags |= ViewItemRenderFlag::Selected;

if (view_->isEditing(child)) {
renderFlags |= ViewItemRenderFlag::Editing;
if (view_->hasEditFocus(child))
renderFlags |= ViewItemRenderFlag::Focused;
}

if (!view_->isValid(child)) {
renderFlags |= ViewItemRenderFlag::Invalid;
}
std::unique_ptr<WWidget> wAfter = view_->itemDelegate(i)->update(w, child, renderFlags);
if (wAfter)
w = wAfter.get();

if (renderFlags.test(ViewItemRenderFlag::Editing))
view_->setEditorWidget(child, w);

if (wAfter) {
setCellWidget(i, std::move(wAfter));

/*
* If we are creating a new editor, then reset its current edit
* state.
*/
if (renderFlags.test(ViewItemRenderFlag::Editing)) {
cpp17::any state = view_->editState(child);
if (cpp17::any_has_value(state))
view_->itemDelegate(i)->setEditState(w, child, state);
}
} else
addColumnStyleClass(i, w);
}
}

void WTreeViewNode::updateGraphics(bool isLast, bool isEmpty)
{
if (index_ == view_->rootIndex())
return;

if (index_.parent() == view_->rootIndex() && !view_->rootIsDecorated()) {
nodeWidget_->bindEmpty("expand");
nodeWidget_->bindEmpty("no-expand");
return;
}

if (!isEmpty) {
ToggleButton *expandButton = nodeWidget_->resolve<ToggleButton *>("expand");
if (!expandButton) {
nodeWidget_->bindEmpty("no-expand");
expandButton =
nodeWidget_->bindWidget
("expand", cpp14::make_unique<ToggleButton>(view_->expandConfig_.get()));

if (WApplication::instance()->environment().agentIsIE())
expandButton->setWidth(19);

expandButton->signal(0).connect(this, &WTreeViewNode::doExpand);
expandButton->signal(1).connect(this, &WTreeViewNode::doCollapse);

expandButton->setState(isExpanded() ? 1 : 0);
}
} else {
WText *noExpandIcon = nodeWidget_->resolve<WText *>("no-expand");
if (!noExpandIcon) {
noExpandIcon
= nodeWidget_->bindWidget("no-expand", cpp14::make_unique<WText>());
noExpandIcon->setInline(false);
noExpandIcon->setStyleClass("Wt-ctrl rh noexpand");
if (WApplication::instance()->environment().agentIsIE())
noExpandIcon->setWidth(19);
}
}

toggleStyleClass("Wt-trunk", !isLast);
nodeWidget_->toggleStyleClass("Wt-end", isLast);
nodeWidget_->toggleStyleClass("Wt-trunk", !isLast);
}

void WTreeViewNode::insertColumns(int column, int count)
{
WContainerWidget *row = nodeWidget_->resolve<WContainerWidget *>("cols-row");

if (view_->columnCount() > 1) {
if (!row) {
std::unique_ptr<WContainerWidget> newRow(new WContainerWidget());

if (view_->rowHeaderCount()) {
newRow->setStyleClass("Wt-tv-rowc rh");
std::unique_ptr<WContainerWidget> rowWrap(new WContainerWidget());
rowWrap->addWidget(std::move(newRow));
newRow = std::move(rowWrap);
}

newRow->setStyleClass("Wt-tv-row rh");

nodeWidget_->bindWidget("cols-row", std::move(newRow));
}
} else
if (row)
row->removeFromParent();

update(0, view_->columnCount() - 1);
}

void WTreeViewNode::removeColumns(int column, int count)
{
insertColumns(0, 0);
}

bool WTreeViewNode::isLast() const
{
return index_ == view_->rootIndex()
|| (index_.row() == view_->model()->rowCount(index_.parent()) - 1);
}

WModelIndex WTreeViewNode::childIndex(int column)
{
return view_->model()->index(index_.row(), column, index_.parent());
}

void WTreeViewNode::addColumnStyleClass(int column, WWidget *w)
{
WStringStream s;

s << view_->columnStyleClass(column) << " Wt-tv-c rh "
<< w->styleClass().toUTF8();

w->setStyleClass(WString::fromUTF8(s.c_str()));
}

void WTreeViewNode::setCellWidget(int column, std::unique_ptr<WWidget> newW)
{
WWidget *current = cellWidget(column);

addColumnStyleClass(column, newW.get());

if (current)
current->setStyleClass(WString::Empty);

if (!WApplication::instance()->environment().ajax()) {
WInteractWidget *wi = dynamic_cast<WInteractWidget *>(newW.get());
if (wi)
wi->clicked().connect
(view_, std::bind(&WTreeView::handleClick, view_, childIndex(column),
std::placeholders::_1));
}

if (column == 0) {
newW->setInline(false);
nodeWidget_->bindWidget("col0", std::move(newW));
} else {
WContainerWidget *row
= nodeWidget_->resolve<WContainerWidget *>("cols-row");
if (view_->rowHeaderCount())
row = dynamic_cast<WContainerWidget *>(row->widget(0));

if (current)
current->removeFromParent();

row->insertWidget(column - 1, std::move(newW));
}
}

WWidget *WTreeViewNode::cellWidget(int column)
{
if (column == 0)
return nodeWidget_->resolveWidget("col0");
else {
WContainerWidget *row
= nodeWidget_->resolve<WContainerWidget *>("cols-row");

if (view_->rowHeaderCount())
row = dynamic_cast<WContainerWidget *>(row->widget(0));

return row->count() >= column ? row->widget(column - 1) : nullptr;
}
}

void WTreeViewNode::doExpand()
{
if (isExpanded())
return;

loadChildren();

ToggleButton *expandButton = nodeWidget_->resolve<ToggleButton *>("expand");
if (expandButton)
expandButton->setState(1);

view_->expandedSet_.insert(index_);

childContainer()->show();

if (parentNode())
parentNode()->adjustChildrenHeight(childrenHeight_);

view_->adjustRenderedNode(this, renderedRow());
view_->scheduleRerender(WTreeView::RenderState::NeedAdjustViewPort);

view_->expanded_.emit(index_);
}

void WTreeViewNode::doCollapse()
{
if (!isExpanded())
return;

ToggleButton *expandButton = nodeWidget_->resolve<ToggleButton *>("expand");
if (expandButton)
expandButton->setState(0);

view_->setCollapsed(index_);

childContainer()->hide();

if (parentNode())
parentNode()->adjustChildrenHeight(-childrenHeight_);

view_->renderedRowsChanged(renderedRow(), -childrenHeight_);

view_->collapsed_.emit(index_);
}

bool WTreeViewNode::isExpanded()
{
return index_ == view_->rootIndex() || !childContainer()->isHidden();
}

void WTreeViewNode::normalizeSpacers()
{
if (childrenLoaded_ && childContainer()->count() == 2) {
RowSpacer *top = topSpacer();
RowSpacer *bottom = bottomSpacer();

if (top && bottom && top != bottom) {
top->setRows(top->rows() + bottom->rows());
if (bottom)
bottom->removeFromParent();
}
}
}

void WTreeViewNode::rerenderSpacers()
{
RowSpacer *s = topSpacer();
if (s)
s->setRows(topSpacerHeight(), true);

s = bottomSpacer();
if (s)
s->setRows(bottomSpacerHeight(), true);
}

bool WTreeViewNode::isAllSpacer()
{
return childrenLoaded_ && topSpacer() && (topSpacer() == bottomSpacer());
}

void WTreeViewNode::loadChildren()
{
if (!childrenLoaded_) {
childrenLoaded_ = true;

view_->expandedSet_.insert(index_);
childrenHeight_ = view_->subTreeHeight(index_) - 1;
view_->expandedSet_.erase(index_);

if (childrenHeight_ > 0)
setTopSpacerHeight(childrenHeight_);
}
}

void WTreeViewNode::adjustChildrenHeight(int diff)
{
childrenHeight_ += diff;

if (isExpanded()) {
WTreeViewNode *parent = parentNode();

if (parent)
parent->adjustChildrenHeight(diff);
else
view_->pageChanged().emit();
}
}

WContainerWidget *WTreeViewNode::childContainer()
{
if (!childContainer_) {
childContainer_ = addWidget(cpp14::make_unique<WContainerWidget>());
childContainer_->setList(true);

if (index_ == view_->rootIndex())
childContainer_->addStyleClass("Wt-tv-root");
}

return childContainer_;
}

WWidget *WTreeViewNode::widgetForModelRow(int modelRow)
{
if (!childrenLoaded_)
return nullptr;

WContainerWidget *c = childContainer();

int first = topSpacer() ? 1 : 0;

if (first < c->count()) {
WTreeViewNode *n = dynamic_cast<WTreeViewNode *>(c->widget(first));
if (n) {
int row = topSpacerHeight();
int index = first + (modelRow - row);

if (index < first)
return topSpacer();
else if (index < c->count())
return c->widget(index);
else
return bottomSpacer();
} else
return bottomSpacer();
} else // isAllSpacer()
return topSpacer();
}

void WTreeViewNode::shiftModelIndexes(int start, int offset)
{
if (!childrenLoaded_)
return;

WContainerWidget *c = childContainer();

int first, end, inc;

if (offset > 0) {
first = c->count() - 1;
end = -1;
inc = -1;
} else {
first = 0;
end = c->count();
inc = 1;
}

for (int i = first; i != end; i += inc) {
WTreeViewNode *n = dynamic_cast<WTreeViewNode *>(c->widget(i));

if (n && n->modelIndex().row() >= start) {
view_->removeRenderedNode(n);

n->index_ = view_->model()->index(n->modelIndex().row() + offset,
n->modelIndex().column(), index_);

// update items through delegate
int lastColumn = view_->columnCount() - 1;
int thisNodeCount = view_->model()->columnCount(index_);

for (int j = 0; j <= lastColumn; ++j) {
WModelIndex child = j < thisNodeCount
? n->childIndex(j) : WModelIndex();
view_->itemDelegate(j)->updateModelIndex(n->cellWidget(j), child);
}

view_->addRenderedNode(n);
}
}
}

int WTreeViewNode::renderedHeight()
{
return index_ == view_->rootIndex() ? childrenHeight_ :
(1 + (isExpanded() ? childrenHeight_ : 0));
}

int WTreeViewNode::topSpacerHeight()
{
RowSpacer *s = topSpacer();

return s ? s->rows() : 0;
}

void WTreeViewNode::setTopSpacerHeight(int rows)
{
if (rows == 0){
childContainer()->removeWidget(topSpacer());
}
else
topSpacer(true)->setRows(rows);
}

void WTreeViewNode::addTopSpacerHeight(int rows)
{
setTopSpacerHeight(topSpacerHeight() + rows);
}

RowSpacer *WTreeViewNode::topSpacer(bool create)
{
WContainerWidget *c = childContainer();

RowSpacer *result = nullptr;
if (c->count() == 0 || !(result = dynamic_cast<RowSpacer *>(c->widget(0)))) {
if (!create)
return nullptr;
else {
result = new RowSpacer(this, 0);
c->insertWidget(0, std::unique_ptr<WWidget>(result));
}
}

return result;
}

int WTreeViewNode::bottomSpacerHeight()
{
RowSpacer *s = bottomSpacer();

return s ? s->rows() : 0;
}

void WTreeViewNode::setBottomSpacerHeight(int rows)
{
if (!rows) {
auto bottom = bottomSpacer();
if (bottom)
bottom->removeFromParent();
} else
bottomSpacer(true)->setRows(rows);
}

void WTreeViewNode::addBottomSpacerHeight(int rows)
{
setBottomSpacerHeight(bottomSpacerHeight() + rows);
}

RowSpacer *WTreeViewNode::bottomSpacer(bool create)
{
WContainerWidget *c = childContainer();

RowSpacer *result = nullptr;
if (c->count() == 0
|| !(result = dynamic_cast<RowSpacer *>(c->widget(c->count() - 1)))) {
if (!create)
return nullptr;
else {
result = c->addWidget(cpp14::make_unique<RowSpacer>(this, 0));
}
}

return result;
}

WTreeViewNode *WTreeViewNode::nextChildNode(WTreeViewNode *prev)
{
if (!childrenLoaded_)
return nullptr;

WContainerWidget *c = childContainer();

int nextI = prev ? c->indexOf(prev) + 1 : topSpacer() ? 1 : 0;

if (nextI < c->count())
return dynamic_cast<WTreeViewNode *>(c->widget(nextI));
else
return nullptr;
}

int WTreeViewNode::renderedRow(int lowerBound, int upperBound)
{
if (!parentNode_)
return 0;
else {
int result = parentNode_->renderedRow(0, upperBound);

if (result > upperBound)
return result;

return result
+ parentNode_->renderedRow(this, lowerBound - result,
upperBound - result);
}
}

int WTreeViewNode::renderedRow(WTreeViewNode *node,
int lowerBound, int upperBound)
{
if (renderedHeight() < lowerBound)
return renderedHeight();

int result = topSpacerHeight();

if (result > upperBound)
return result;

for (WTreeViewNode *c = nextChildNode(nullptr); c; c = nextChildNode(c)) {
if (c == node)
return result;
else {
result += c->renderedHeight();
if (result > upperBound)
return result;
}
}

assert(false);
return 0;
}

void WTreeViewNode::renderSelected(bool selected, int column)
{
std::string cl = WApplication::instance()->theme()->activeClass();

if (view_->selectionBehavior() == SelectionBehavior::Rows) {
nodeWidget_->toggleStyleClass(cl, selected);
} else {
WWidget *w = cellWidget(column);
w->toggleStyleClass(cl, selected);
}
}

void WTreeViewNode::selfCheck()
{
assert(renderedHeight() == view_->subTreeHeight(index_));

int childNodesHeight = 0;
for (WTreeViewNode *c = nextChildNode(nullptr); c; c = nextChildNode(c)) {
c->selfCheck();
childNodesHeight += c->renderedHeight();
}

if (childNodesHeight == 0) {
assert(topSpacer() == bottomSpacer());
assert(topSpacerHeight() == childrenHeight());
} else {
assert(topSpacerHeight() + childNodesHeight + bottomSpacerHeight()
== childrenHeight());
}
}

WTreeView::WTreeView()
: skipNextMouseEvent_(false),
renderedNodesAdded_(false),
rootNode_(nullptr),
rowHeightRule_(nullptr),
rowWidthRule_(nullptr),
rowContentsWidthRule_(nullptr),
c0StyleRule_(nullptr),
rootIsDecorated_(true),
viewportTop_(0),
viewportHeight_(UNKNOWN_VIEWPORT_HEIGHT),
firstRenderedRow_(0),
validRowCount_(0),
nodeLoad_(0),
headerContainer_(nullptr),
contentsContainer_(nullptr),
scrollBarC_(nullptr),
firstRemovedRow_(0),
removedHeight_(0),
itemEvent_(impl_, "itemEvent"),
itemTouchEvent_(impl_, "itemTouchEvent")
{
setSelectable(false);

expandConfig_.reset(new ToggleButtonConfig(this, "Wt-ctrl rh "));
expandConfig_->addState("expand");
expandConfig_->addState("collapse");
expandConfig_->generate();

setStyleClass("Wt-itemview Wt-treeview");

const char *CSS_RULES_NAME = "Wt::WTreeView";

WApplication *app = WApplication::instance();

if (app->environment().agentIsWebKit() || app->environment().agentIsOpera())
if (!app->styleSheet().isDefined(CSS_RULES_NAME))
/* bottom scrollbar */
addCssRule
(".Wt-treeview .Wt-tv-rowc", "position: relative;", CSS_RULES_NAME);

setup();
}

void WTreeView::setup()
{
WApplication *app = WApplication::instance();

impl_->clear();

rootNode_ = nullptr;

/*
* Setup main layout
*/
headers_ = new WContainerWidget();
headers_->setStyleClass("Wt-headerdiv headerrh");

contents_ = new WContainerWidget();
WContainerWidget *wrapRoot
= contents_->addWidget(cpp14::make_unique<WContainerWidget>());

if (app->environment().agentIsIE()) {
wrapRoot->setAttributeValue("style", "zoom: 1");
contents_->setAttributeValue("style", "zoom: 1");
}

if (app->environment().ajax()) {
impl_->setPositionScheme(PositionScheme::Relative);

std::unique_ptr<WVBoxLayout> layout(new WVBoxLayout());
layout->setSpacing(0);
layout->setContentsMargins(0, 0, 0, 0);

headerContainer_ = new WContainerWidget();
headerContainer_->setOverflow(Overflow::Hidden);
headerContainer_->setStyleClass("Wt-header headerrh cwidth");
headerContainer_->addWidget(std::unique_ptr<WWidget>(headers_));

contentsContainer_ = new ContentsContainer(this);
contentsContainer_->setStyleClass("cwidth");
contentsContainer_->setOverflow(Overflow::Auto);
contentsContainer_->scrolled().connect(this, &WTreeView::onViewportChange);
contentsContainer_->addWidget(std::unique_ptr<WWidget>(contents_));

layout->addWidget(std::unique_ptr<WWidget>(headerContainer_));
layout->addWidget(std::unique_ptr<WWidget>(contentsContainer_), 1);

impl_->setLayout(std::move(layout));
} else {
contentsContainer_ = new WContainerWidget();
contentsContainer_->addWidget(std::unique_ptr<WWidget>(contents_));
contentsContainer_->setOverflow(Overflow::Hidden);

impl_->setPositionScheme(PositionScheme::Relative);
contentsContainer_->setPositionScheme(PositionScheme::Relative);
contents_->setPositionScheme(PositionScheme::Relative);

impl_->addWidget(std::unique_ptr<WWidget>(headers_));
impl_->addWidget(std::unique_ptr<WWidget>(contentsContainer_));

viewportHeight_ = 1000;

resize(width(), height());
}

setRowHeight(rowHeight());
}

void WTreeView::defineJavaScript()
{
WApplication *app = WApplication::instance();

if (!app->environment().ajax())
return;

LOAD_JAVASCRIPT(app, "js/WTreeView.js", "WTreeView", wtjs1);

setJavaScriptMember(" WTreeView", "new " WT_CLASS ".WTreeView("
+ app->javaScriptClass() + "," + jsRef() + ","
+ contentsContainer_->jsRef() + ","
+ headerContainer_->jsRef() + ","
+ std::to_string(rowHeaderCount())+ ",'"
+ WApplication::instance()->theme()->activeClass()
+ "');");

setJavaScriptMember(WT_RESIZE_JS,
"function(self,w,h) {"
"$(self).data('obj').wtResize();"
"}");
}

void WTreeView::setRowHeaderCount(int count)
{
WApplication *app = WApplication::instance();

// This kills progressive enhancement too
if (!app->environment().ajax())
return;

int oldCount = rowHeaderCount();

if (count != 0 && count != 1)
throw WException("WTreeView::setRowHeaderCount: count must be 0 or 1");

WAbstractItemView::setRowHeaderCount(count);

if (count && !oldCount) {
addStyleClass("column1");
WContainerWidget *rootWrap
= dynamic_cast<WContainerWidget *>(contents_->widget(0));
rootWrap->setWidth(WLength(100, LengthUnit::Percentage));
rootWrap->setOverflow(Overflow::Hidden);
contents_->setPositionScheme(PositionScheme::Relative);
rootWrap->setPositionScheme(PositionScheme::Absolute);

bool useStyleLeft
= app->environment().agentIsWebKit()
|| app->environment().agentIsOpera();

if (useStyleLeft) {
bool rtl = app->layoutDirection() == LayoutDirection::RightToLeft;

tieRowsScrollJS_.setJavaScript
("function(obj, event) {"
"" WT_CLASS ".getCssRule('#" + id() + " .Wt-tv-rowc').style.left"
"" "= -obj.scrollLeft "
+ (rtl ? "+ (obj.firstChild.offsetWidth - obj.offsetWidth)" : "")
+ "+ 'px';"
"}");
} else {
/*
* this is for some reason very very slow in webkit, and with
* application/xml on Firefox (jQuery suffers)
*/
tieRowsScrollJS_.setJavaScript
("function(obj, event) {"
"$('#" + id() + " .Wt-tv-rowc').parent().scrollLeft(obj.scrollLeft);"
"}");
}

WContainerWidget *scrollBarContainer = new WContainerWidget();
scrollBarContainer->setStyleClass("cwidth");
scrollBarContainer->setHeight(SCROLLBAR_WIDTH);
scrollBarC_
= scrollBarContainer->addWidget(cpp14::make_unique<WContainerWidget>());
scrollBarC_->setStyleClass("Wt-tv-row Wt-scroll");
scrollBarC_->scrolled().connect(tieRowsScrollJS_);

if (app->environment().agentIsIE()) {
scrollBarContainer->setPositionScheme(PositionScheme::Relative);
bool rtl = app->layoutDirection() == LayoutDirection::RightToLeft;
scrollBarC_->setAttributeValue("style",
std::string(rtl ? "left:" : "right:")
+ "0px");
// and still it doesn't work properly...
}

WContainerWidget *scrollBar
= scrollBarC_->addWidget(cpp14::make_unique<WContainerWidget>());
scrollBar->setStyleClass("Wt-tv-rowc");
if (useStyleLeft)
scrollBar->setAttributeValue("style", "left: 0px;");
impl_->layout()->addWidget(std::unique_ptr<WWidget>(scrollBarContainer));
}
}

WTreeView::~WTreeView()
{
wApp->styleSheet().removeRule(rowHeightRule_);
wApp->styleSheet().removeRule(rowWidthRule_);
wApp->styleSheet().removeRule(rowContentsWidthRule_);
wApp->styleSheet().removeRule(c0StyleRule_);

impl_->clear();
}

std::string WTreeView::columnStyleClass(int column) const
{
return columnInfo(column).styleClass();
}

void WTreeView::setColumnWidth(int column, const WLength& width)
{
if (!width.isAuto())
columnInfo(column).width = WLength(round(width.value()), width.unit());
else
columnInfo(column).width = WLength::Auto;

WWidget *toResize = columnInfo(column).styleRule->templateWidget();
toResize->setWidth(0);
toResize->setWidth(columnInfo(column).width.toPixels());

WApplication *app = WApplication::instance();

if (app->environment().ajax() &&
static_cast<unsigned int>(renderState_) <
static_cast<unsigned int>(RenderState::NeedRerenderHeader))
doJavaScript("$('#" + id() + "').data('obj').adjustColumns();");

if (!app->environment().ajax() && column == 0 && !width.isAuto()) {
double total = 0;
for (int i = 0; i < columnCount(); ++i)
if (!columnInfo(i).hidden)
total += columnWidth(i).toPixels();

resize(total, height());
}
}

void WTreeView::setColumnHidden(int column, bool hidden)
{
if (columnInfo(column).hidden != hidden) {
WAbstractItemView::setColumnHidden(column, hidden);

WWidget *toHide = columnInfo(column).styleRule->templateWidget();
toHide->setHidden(hidden);

setColumnWidth(column, columnWidth(column));
}
}

void WTreeView::setHeaderHeight(const WLength& height)
{
WAbstractItemView::setHeaderHeight(height);
}

void WTreeView::setRootIsDecorated(bool show)
{
rootIsDecorated_ = show;
}

void WTreeView::setAlternatingRowColors(bool enable)
{
WAbstractItemView::setAlternatingRowColors(enable);
setRootNodeStyle();
}

void WTreeView::setRootNodeStyle()
{
if (!rootNode_)
return;

if (alternatingRowColors())
rootNode_->decorationStyle().setBackgroundImage
(WLink(WApplication::instance()->theme()->resourcesUrl()
+ "stripes/stripe-" + std::to_string
(static_cast<int>(rowHeight().toPixels())) + "px.gif"));
else
rootNode_->decorationStyle().setBackgroundImage(WLink(""));
}

void WTreeView::setRowHeight(const WLength& rowHeight)
{
WAbstractItemView::setRowHeight(rowHeight);

if (rowHeightRule_) {
rowHeightRule_->templateWidget()->setHeight(rowHeight);
rowHeightRule_->templateWidget()->setLineHeight(rowHeight);
}

if (!WApplication::instance()->environment().ajax() && !height().isAuto())
viewportHeight_ = static_cast<int>(contentsContainer_->height().toPixels()
/ rowHeight.toPixels());

setRootNodeStyle();

for (NodeMap::const_iterator i = renderedNodes_.begin();
i != renderedNodes_.end(); ++i)
i->second->rerenderSpacers();

if (rootNode_)
scheduleRerender(RenderState::NeedAdjustViewPort);
}

void WTreeView::resize(const WLength& width, const WLength& height)
{
WApplication *app = WApplication::instance();
WLength w = app->environment().ajax() ? WLength::Auto : width;

if (app->environment().ajax())
contentsContainer_->setWidth(w);
if (headerContainer_)
headerContainer_->setWidth(w);

if (!height.isAuto()) {
if (!app->environment().ajax()) {
if (impl_->count() < 3)
impl_->addWidget(createPageNavigationBar());

double navigationBarHeight = 35;
double headerHeight = this->headerHeight().toPixels();

int h = (int)(height.toPixels() - navigationBarHeight - headerHeight);
contentsContainer_->setHeight(std::max(h, (int)rowHeight().value()));

viewportHeight_
= static_cast<int>(contentsContainer_->height().toPixels()
/ rowHeight().toPixels());
} else
viewportHeight_ = static_cast<int>
(std::ceil(height.toPixels() / rowHeight().toPixels()));
} else {
if (app->environment().ajax())
viewportHeight_ = UNKNOWN_VIEWPORT_HEIGHT;

scheduleRerender(RenderState::NeedAdjustViewPort);
}

WCompositeWidget::resize(width, height);
}

int WTreeView::calcOptimalFirstRenderedRow() const
{
if (WApplication::instance()->environment().ajax())
return std::max(0, viewportTop_ - viewportHeight_ - viewportHeight_ / 2);
else
return viewportTop_;
}

int WTreeView::calcOptimalRenderedRowCount() const
{
if (WApplication::instance()->environment().ajax())
return 4 * viewportHeight_;
else
return viewportHeight_ + 5; // some margin... something inaccurate going on?
}

void WTreeView::setModel(const std::shared_ptr<WAbstractItemModel>& model)
{
WAbstractItemView::setModel(model);

typedef WTreeView Self;

/* connect slots to new model */
modelConnections_.push_back(model->columnsInserted().connect
(this, &Self::modelColumnsInserted));
modelConnections_.push_back(model->columnsAboutToBeRemoved().connect
(this, &Self::modelColumnsAboutToBeRemoved));
modelConnections_.push_back(model->columnsRemoved().connect
(this, &Self::modelColumnsRemoved));
modelConnections_.push_back(model->rowsInserted().connect
(this, &Self::modelRowsInserted));
modelConnections_.push_back(model->rowsAboutToBeRemoved().connect
(this, &Self::modelRowsAboutToBeRemoved));
modelConnections_.push_back(model->rowsRemoved().connect
(this, &Self::modelRowsRemoved));
modelConnections_.push_back(model->dataChanged().connect
(this, &Self::modelDataChanged));
modelConnections_.push_back(model->headerDataChanged().connect
(this, &Self::modelHeaderDataChanged));
modelConnections_.push_back(model->layoutAboutToBeChanged().connect
(this, &Self::modelLayoutAboutToBeChanged));
modelConnections_.push_back(model->layoutChanged().connect
(this, &Self::modelLayoutChanged));
modelConnections_.push_back(model->modelReset().connect
(this, &Self::modelReset));

expandedSet_.clear();

WApplication *app = WApplication::instance();
while (static_cast<int>(columns_.size()) > model->columnCount()) {
app->styleSheet().removeRule(columns_.back().styleRule.get());
columns_.erase(columns_.begin() + columns_.size() - 1);
}

pageChanged().emit();
}

void WTreeView::scheduleRerender(RenderState what)
{
if (what == RenderState::NeedRerender || what == RenderState::NeedRerenderData) {
if(rootNode_){
rootNode_->removeFromParent();
rootNode_ = nullptr;
}
}

WAbstractItemView::scheduleRerender(what);
}

void WTreeView::render(WFlags<RenderFlag> flags)
{
WApplication *app = WApplication::instance();

if (flags.test(RenderFlag::Full)) {
defineJavaScript();

if (!itemTouchEvent_.isConnected())
itemTouchEvent_.connect(this, &WTreeView::onItemTouchEvent);

if (!itemEvent_.isConnected()) {
itemEvent_.connect(this, &WTreeView::onItemEvent);

addCssRule("#" + id() + " .cwidth", "");

rowHeightRule_ = app->styleSheet().addRule
(cpp14::make_unique<WCssTemplateRule>("#" + id() + " .rh"));
rowHeightRule_->templateWidget()->setHeight(rowHeight());
rowHeightRule_->templateWidget()->setLineHeight(rowHeight());

rowWidthRule_ = app->styleSheet().addRule
(cpp14::make_unique<WCssTemplateRule>("#" + id() + " .Wt-tv-row"));
rowContentsWidthRule_ = app->styleSheet().addRule
(cpp14::make_unique<WCssTemplateRule>("#" + id() + " .Wt-tv-rowc"));

if (app->environment().ajax()) {
contentsContainer_->scrolled().connect
("function(obj, event) {"
/*
* obj.sb: workaround for Konqueror to prevent recursive
* invocation because reading scrollLeft triggers onscroll()
*/
"""if (obj.sb) return;"
"""obj.sb = true;"
"" + headerContainer_->jsRef() + ".scrollLeft=obj.scrollLeft;"
/* the following is a workaround for IE7 */
"""var t = " + contents_->jsRef() + ".firstChild;"
"""var h = " + headers_->jsRef() + ";"
"""h.style.width = (t.offsetWidth - 1) + 'px';"
"""h.style.width = t.offsetWidth + 'px';"
"""obj.sb = false;"
"}");
}

c0StyleRule_ = addCssRule("#" + id() + " li .none",
"width: auto;"
"text-overflow: ellipsis;"
"overflow: hidden");
if (columns_.size() > 0) {
ColumnInfo& ci = columnInfo(0);
c0StyleRule_->setSelector("#" + id() + " li ." + ci.styleClass());
}
}
}

while (renderState_ != RenderState::RenderOk) {
RenderState s = renderState_;
renderState_ = RenderState::RenderOk;

switch (s) {
case RenderState::NeedRerender:
rerenderHeader();
rerenderTree();
break;
case RenderState::NeedRerenderHeader:
rerenderHeader();
break;
case RenderState::NeedRerenderData:
rerenderTree();
break;
case RenderState::NeedAdjustViewPort:
adjustToViewport();
break;
default:
break;
}
}

if (app->environment().ajax() && rowHeaderCount() && renderedNodesAdded_) {
doJavaScript("{var s=" + scrollBarC_->jsRef() + ";"
"""if (s) {" + tieRowsScrollJS_.execJs("s") + "}"
"}");
renderedNodesAdded_ = false;
}

// update the rowHeight (needed for scrolling fix)
WStringStream s;
s << "jQuery.data(" << jsRef()
<< ", 'obj').setRowHeight("
<< static_cast<int>(this->rowHeight().toPixels())
<< ");";

if (app->environment().ajax())
doJavaScript(s.str());

WAbstractItemView::render(flags);
}

void WTreeView::rerenderHeader()
{
WApplication *app = WApplication::instance();

saveExtraHeaderWidgets();
headers_->clear();

WContainerWidget *row
= headers_->addWidget(cpp14::make_unique<WContainerWidget>());
row->setFloatSide(Side::Right);

if (rowHeaderCount()) {
row->setStyleClass("Wt-tv-row headerrh background");
row = row->addWidget(cpp14::make_unique<WContainerWidget>());
row->setStyleClass("Wt-tv-rowc headerrh");
} else
row->setStyleClass("Wt-tv-row");

for (int i = 0; i < columnCount(); ++i) {
std::unique_ptr<WWidget> w = createHeaderWidget(i);

if (i != 0) {
w->setFloatSide(Side::Left);
row->addWidget(std::move(w));
} else
headers_->addWidget(std::move(w));
}

if (app->environment().ajax())
doJavaScript("$('#" + id() + "').data('obj').adjustColumns();");
}

void WTreeView::enableAjax()
{
saveExtraHeaderWidgets();

setup();
defineJavaScript();

scheduleRerender(RenderState::NeedRerender);

WAbstractItemView::enableAjax();
}

void WTreeView::rerenderTree()
{
WContainerWidget *wrapRoot
= dynamic_cast<WContainerWidget *>(contents_->widget(0));

bool firstTime = rootNode_ == nullptr;
wrapRoot->clear();

firstRenderedRow_ = calcOptimalFirstRenderedRow();
validRowCount_ = 0;

rootNode_ = wrapRoot->addWidget
(cpp14::make_unique<WTreeViewNode>(this, rootIndex(), -1, true, nullptr));

if (WApplication::instance()->environment().ajax()) {

if (editTriggers().test(EditTrigger::SingleClicked) ||
clicked().isConnected()) {
connectObjJS(rootNode_->clicked(), "click");
if (firstTime)
connectObjJS(contentsContainer_->clicked(), "rootClick");
}

if (editTriggers().test(EditTrigger::DoubleClicked) ||
doubleClicked().isConnected()) {
connectObjJS(rootNode_->doubleClicked(), "dblClick");
if (firstTime)
connectObjJS(contentsContainer_->doubleClicked(), "rootDblClick");
}

connectObjJS(rootNode_->mouseWentDown(), "mouseDown");
if (firstTime)
connectObjJS(contentsContainer_->mouseWentDown(), "rootMouseDown");

if (mouseWentUp().isConnected()) {
// Do not stop propagation to avoid mouseDrag event being emitted
connectObjJS(rootNode_->mouseWentUp(), "mouseUp");
if (firstTime)
connectObjJS(contentsContainer_->mouseWentUp(), "rootMouseUp");
}

#ifdef WT_CNOR
// workaround because cnor is a bit dumb and does not understand that it
// can convert EventSignal<TouchEvent>& to EventSignalBase&
EventSignalBase& a = rootNode_->touchStarted();
#endif
connectObjJS(rootNode_->touchStarted(), "touchStart");
connectObjJS(rootNode_->touchMoved(), "touchMove");
connectObjJS(rootNode_->touchEnded(), "touchEnd");
}

setRootNodeStyle();

pageChanged().emit();

adjustToViewport();
}

void WTreeView::onViewportChange(WScrollEvent e)
{
viewportTop_ = static_cast<int>
(std::floor(e.scrollY() / rowHeight().toPixels()));

contentsSizeChanged(0, e.viewportHeight());
}

void WTreeView::contentsSizeChanged(int width, int height)
{
viewportHeight_
= static_cast<int>(std::ceil(height / rowHeight().toPixels()));

scheduleRerender(RenderState::NeedAdjustViewPort);
}

void WTreeView::onItemEvent(std::string nodeAndColumnId, std::string type,
std::string extra1, std::string extra2,
WMouseEvent event)
{
// nodeId and columnId are combined because WSignal needed to be changed
// since MSVS 2012 does not support >5 arguments in std::bind()
WModelIndex index = calculateModelIndex(nodeAndColumnId);

/*
* Every mouse event is emitted twice (because we don't prevent
* the propagation because it will block the mouseWentUp event
* and therefore result in mouseDragged being emitted (See #3879)
*/
if (nodeAndColumnId.empty() && skipNextMouseEvent_) {
skipNextMouseEvent_ = false;
return;
} else if (!nodeAndColumnId.empty()) {
skipNextMouseEvent_ = true;
}

if (type == "clicked") {
handleClick(index, event);
} else if (type == "dblclicked") {
handleDoubleClick(index, event);
} else if (type == "mousedown") {
handleMouseDown(index, event);
} else if (type == "mouseup") {
handleMouseUp(index, event);
} else if (type == "drop") {
WDropEvent e(WApplication::instance()->decodeObject(extra1), extra2, event);
dropEvent(e, index);
}
}

void WTreeView::onItemTouchEvent(std::string nodeAndColumnId, std::string type, WTouchEvent event)
{
// nodeId and columnId are combined because WSignal needed to be changed
// since MSVS 2012 does not support >5 arguments in std::bind()
std::vector<WModelIndex> index;
index.push_back(calculateModelIndex(nodeAndColumnId));

if (type == "touchselect")
handleTouchSelect(index, event);
else if (type == "touchstart")
handleTouchStart(index, event);
else if (type == "touchend")
handleTouchEnd(index, event);
}

WModelIndex WTreeView::calculateModelIndex(std::string nodeAndColumnId)
{
std::vector<std::string> nodeAndColumnSplit;
boost::split(nodeAndColumnSplit, nodeAndColumnId, boost::is_any_of(":"));

WModelIndex index;

if (nodeAndColumnSplit.size() == 2) {
std::string nodeId = nodeAndColumnSplit[0];
int columnId = -1;
try {
columnId = Utils::stoi(std::string(nodeAndColumnSplit[1]));
} catch (std::exception& e) {
LOG_ERROR("WTreeview::calculateModelIndex: bad value for format 1: "
<< nodeAndColumnSplit[1]);
}

int column = (columnId == 0 ? 0 : -1);
for (unsigned i = 0; i < columns_.size(); ++i)
if (columns_[i].id == columnId) {
column = i;
break;
}

if (column != -1) {
WModelIndex c0index;
for (NodeMap::const_iterator i = renderedNodes_.begin();
i != renderedNodes_.end(); ++i) {
if (i->second->id() == nodeId) {
c0index = i->second->modelIndex();
break;
}
}

if (c0index.isValid())
index = model()->index(c0index.row(), column, c0index.parent());
else
LOG_ERROR("WTreeView::calculateModelIndex: illegal node id: " << nodeId);
}
}
return index;
}

int WTreeView::subTreeHeight(const WModelIndex& index,
int lowerBound, int upperBound) const
{
int result = 0;

if (index != rootIndex())
++result;

if (result >= upperBound)
return result;

if (model() && isExpanded(index)) {
int childCount = model()->rowCount(index);

for (int i = 0; i < childCount; ++i) {
WModelIndex childIndex = model()->index(i, 0, index);

result += subTreeHeight(childIndex, upperBound - result);

if (result >= upperBound)
return result;
}
}

return result;
}

bool WTreeView::isExpanded(const WModelIndex& index) const
{
return index == rootIndex()
|| expandedSet_.find(index) != expandedSet_.end();
}

bool WTreeView::isExpandedRecursive(const WModelIndex& index) const
{
if (isExpanded(index)) {
if (index != rootIndex())
return isExpanded(index.parent());
else
return false;
} else
return false;
}

void WTreeView::setCollapsed(const WModelIndex& index)
{
expandedSet_.erase(index);

/*
* Deselecting everything that is collapsed is not consistent with
* the allowed initial state. If the user wants this, he can implement
* this himself.
*/
#if 0
bool selectionHasChanged = false;
WModelIndexSet& selection = selectionModel()->selection_;

WModelIndexSet toDeselect;
for (WModelIndexSet::iterator it = selection.lower_bound(index);
it != selection.end(); ++it) {
WModelIndex i = *it;
if (i == index) {
} else if (WModelIndex::isAncestor(i, index)) {
toDeselect.insert(i);
} else
break;
}

for (WModelIndexSet::iterator it = toDeselect.begin();
it != toDeselect.end(); ++it)
if (internalSelect(*it, SelectionFlag::Deselect))
selectionHasChanged = true;

if (selectionHasChanged)
selectionChanged().emit();
#endif
}

void WTreeView::setExpanded(const WModelIndex& index, bool expanded)
{
if (isExpanded(index) != expanded) {
WWidget *w = widgetForIndex(index);

WTreeViewNode *node = w ? dynamic_cast<WTreeViewNode *>(w) : nullptr;

if (node) {
if (expanded)
node->doExpand();
else
node->doCollapse();
} else {
int height = subTreeHeight(index);

if (expanded)
expandedSet_.insert(index);
else
setCollapsed(index);

if (w) {
RowSpacer *spacer = dynamic_cast<RowSpacer *>(w);

int diff = subTreeHeight(index) - height;

spacer->setRows(spacer->rows() + diff);
spacer->node()->adjustChildrenHeight(diff);

renderedRowsChanged(renderedRow(index, spacer,
renderLowerBound(), renderUpperBound()),
diff);
}
}
}
}

void WTreeView::expand(const WModelIndex& index)
{
setExpanded(index, true);
}

void WTreeView::collapse(const WModelIndex& index)
{
setExpanded(index, false);
}

void WTreeView::expandToDepth(int depth)
{
if (depth > 0)
expandChildrenToDepth(rootIndex(), depth);
}

void WTreeView::expandChildrenToDepth(const WModelIndex& index, int depth)
{
for (int i = 0; i < model()->rowCount(index); ++i) {
WModelIndex c = model()->index(i, 0, index);

expand(c);

if (depth > 1)
expandChildrenToDepth(c, depth - 1);
}
}

WWidget *WTreeView::itemWidget(const WModelIndex& index) const
{
if (!index.isValid())
return nullptr;

WTreeViewNode *n = nodeForIndex(index);
if (n)
return n->cellWidget(index.column());
else
return nullptr;
}

/*
* Returns the widget that renders the node indicated by index.
*
* It may be:
* - a tree node (node->modelIndex() == index)
* - 0 if index is not somewhere in column 0
* - a spacer which includes the 'index', when all intermediate
* nodes are expanded, or
* - 0 otherwise
*/
WWidget *WTreeView::widgetForIndex(const WModelIndex& index) const
{
if (!index.isValid())
return rootNode_;

if (index.column() != 0)
return nullptr;

NodeMap::const_iterator i = renderedNodes_.find(index);

if (i != renderedNodes_.end())
return i->second;
else {
if (!isExpanded(index.parent()))
return nullptr;

WWidget *parent = widgetForIndex(index.parent());
WTreeViewNode *parentNode = dynamic_cast<WTreeViewNode *>(parent);

if (parentNode) {
int row = getIndexRow(index, parentNode->modelIndex(), 0,
std::numeric_limits<int>::max());
return parentNode->widgetForModelRow(row);
} else
return parent;
}
}

void WTreeView::modelColumnsInserted(const WModelIndex& parent,
int start, int end)
{
int count = end - start + 1;
if (!parent.isValid()) {

WApplication *app = WApplication::instance();
for (int i = start; i < start + count; ++i)
columns_.insert(columns_.begin() + i, createColumnInfo(i));

if (static_cast<unsigned int>(renderState_) <
static_cast<unsigned int>(RenderState::NeedRerenderHeader)) {
if (start == 0)
scheduleRerender(RenderState::NeedRerenderHeader);
else {
if (app->environment().ajax())
doJavaScript("$('#" + id() + "').data('obj').adjustColumns();");

WContainerWidget *row = headerRow();

for (int i = start; i < start + count; ++i) {
std::unique_ptr<WWidget> w = createHeaderWidget(i);
w->setFloatSide(Side::Left);
row->insertWidget(i - 1, std::move(w));
}
}
}
}

if (renderState_ == RenderState::NeedRerender ||
renderState_ == RenderState::NeedRerenderData)
return;

if (start == 0)
scheduleRerender(RenderState::NeedRerenderData);
else {
WTreeViewNode *node = nodeForIndex(parent);
if (node)
for (WTreeViewNode *c = node->nextChildNode(nullptr); c;
c = node->nextChildNode(c))
c->insertColumns(start, count);
}
}

void WTreeView::modelColumnsAboutToBeRemoved(const WModelIndex& parent,
int start, int end)
{
int count = end - start + 1;
if (!parent.isValid()) {
WApplication *app = wApp;

if (static_cast<unsigned int>(renderState_) <
static_cast<unsigned int>(RenderState::NeedRerenderHeader)) {
if (app->environment().ajax())
doJavaScript("$('#" + id() + "').data('obj').adjustColumns();");
}

for (int i=start; i<start+count; i++)
app->styleSheet().removeRule(columns_[i].styleRule.get());
columns_.erase(columns_.begin() + start, columns_.begin() + start + count);

if (static_cast<unsigned int>(renderState_) <
static_cast<unsigned int>(RenderState::NeedRerenderHeader)) {
if (start == 0)
scheduleRerender(RenderState::NeedRerenderHeader);
else {
for (int i = start; i < start + count; ++i) {
auto w = headerWidget(start, false);
if (w)
w->removeFromParent();
}
}
}
}

if (start == 0)
scheduleRerender(RenderState::NeedRerenderData);
}

void WTreeView::modelColumnsRemoved(const WModelIndex& parent,
int start, int end)
{
if (renderState_ == RenderState::NeedRerender ||
renderState_ == RenderState::NeedRerenderData)
return;

int count = end - start + 1;

if (start != 0) {
WTreeViewNode *node = nodeForIndex(parent);
if (node)
for (WTreeViewNode *c = node->nextChildNode(nullptr); c;
c = node->nextChildNode(c))
c->removeColumns(start, count);
}

if (start <= currentSortColumn_ && currentSortColumn_ <= end)
currentSortColumn_ = -1;
}

void WTreeView::modelRowsInserted(const WModelIndex& parent,
int start, int end)
{
int count = end - start + 1;
shiftModelIndexes(parent, start, count);

if (renderState_ == RenderState::NeedRerender ||
renderState_ == RenderState::NeedRerenderData)
return;

WWidget *parentWidget = widgetForIndex(parent);

bool renderedRowsChange = isExpandedRecursive(parent);

if (parentWidget) {
WTreeViewNode *parentNode = dynamic_cast<WTreeViewNode *>(parentWidget);

if (parentNode) {
if (parentNode->childrenLoaded()) {
WWidget *startWidget = nullptr;

/*
* First we decide between inserting in the top spacer, bottom spacer
* and in actually rendered nodes.
*/
if (end < model()->rowCount(parent) - 1)
startWidget = parentNode->widgetForModelRow(start);
else if (parentNode->bottomSpacerHeight() != 0)
startWidget = parentNode->bottomSpacer();

parentNode->adjustChildrenHeight(count);
parentNode->shiftModelIndexes(start, count);

if (startWidget && startWidget == parentNode->topSpacer()) {
parentNode->addTopSpacerHeight(count);
if (renderedRowsChange)
renderedRowsChanged(renderedRow(model()->index(start, 0, parent),
parentNode->topSpacer(),
renderLowerBound(),
renderUpperBound()),
count);

} else if (startWidget && startWidget == parentNode->bottomSpacer()) {
parentNode->addBottomSpacerHeight(count);
if (renderedRowsChange)
renderedRowsChanged(renderedRow(model()->index(start, 0, parent),
parentNode->bottomSpacer(),
renderLowerBound(),
renderUpperBound()),
count);
} else {
int maxRenderHeight
= firstRenderedRow_ + std::max(validRowCount_, viewportHeight_)
- parentNode->renderedRow() - parentNode->topSpacerHeight();

int containerIndex = startWidget ? parentNode->childContainer()
->indexOf(startWidget) : parentNode->childContainer()->count();

int parentRowCount = model()->rowCount(parent);

int nodesToAdd = std::max(0, std::min(count, maxRenderHeight));

WTreeViewNode *first = nullptr;
for (int i = 0; i < nodesToAdd; ++i) {
std::unique_ptr<WTreeViewNode> n
(new WTreeViewNode(this, model()->index(start + i, 0, parent),
-1, start + i == parentRowCount - 1,
parentNode));
if (!first)
first = n.get();

parentNode->childContainer()->insertWidget(containerIndex + i,
std::move(n));

if (renderedRowsChange)
++validRowCount_;

}

if (nodesToAdd < count) {
parentNode->addBottomSpacerHeight(count - nodesToAdd);

// +1 for bottom spacer
int targetSize = containerIndex + nodesToAdd + 1;

int extraBottomSpacer = 0;
while (parentNode->childContainer()->count() > targetSize) {
WTreeViewNode *n
= dynamic_cast<WTreeViewNode *>(parentNode->childContainer()
->widget(targetSize - 1));
assert(n);
extraBottomSpacer += n->renderedHeight();

if (renderedRowsChange)
validRowCount_ -= n->renderedHeight();

n->removeFromParent();
}

if (extraBottomSpacer)
parentNode->addBottomSpacerHeight(extraBottomSpacer);

parentNode->normalizeSpacers();
}

if (first && renderedRowsChange)
renderedRowsChanged(first->renderedRow(renderLowerBound(),
renderUpperBound()),
nodesToAdd);

// Update graphics if the last node has changed, i.e. if we are
// adding rows at the back
if (end == model()->rowCount(parent) - 1 && start >= 1) {
WTreeViewNode *n = dynamic_cast<WTreeViewNode *>
(parentNode->widgetForModelRow(start - 1));

if (n)
n->updateGraphics(false, !model()->hasChildren(n->modelIndex()));
}
}
} /* else:
children not loaded -- so we do not need to bother
*/

// Update graphics for parent when first children have een added
if (model()->rowCount(parent) == count)
parentNode->updateGraphics(parentNode->isLast(), false);
} else {
if (isExpanded(parent)) {
RowSpacer *s = dynamic_cast<RowSpacer *>(parentWidget);

s->setRows(s->rows() + count);
s->node()->adjustChildrenHeight(count);

if (renderedRowsChange)
renderedRowsChanged
(renderedRow(model()->index(start, 0, parent), s,
renderLowerBound(), renderUpperBound()),
count);
}
}
} else {
/*
* parentWidget is 0: it means it is not even part of any spacer.
*/
}
}

void WTreeView::modelRowsAboutToBeRemoved(const WModelIndex& parent,
int start, int end)
{
int count = end - start + 1;

bool renderedRowsChange = isExpandedRecursive(parent);

if (renderState_ != RenderState::NeedRerender &&
renderState_ != RenderState::NeedRerenderData) {
firstRemovedRow_ = -1;
removedHeight_ = 0;

WWidget *parentWidget = widgetForIndex(parent);

if (parentWidget) {
WTreeViewNode *parentNode = dynamic_cast<WTreeViewNode *>(parentWidget);

if (parentNode) {
if (parentNode->childrenLoaded()) {
for (int i = end; i >= start; --i) {
WWidget *w = parentNode->widgetForModelRow(i);
assert(w);

RowSpacer *s = dynamic_cast<RowSpacer *>(w);
if (s) {
WModelIndex childIndex = model()->index(i, 0, parent);

if (i == start && renderedRowsChange)
firstRemovedRow_ = renderedRow(childIndex, w);

int childHeight = subTreeHeight(childIndex);

if (renderedRowsChange)
removedHeight_ += childHeight;

s->setRows(s->rows() - childHeight);
} else {
WTreeViewNode *node = dynamic_cast<WTreeViewNode *>(w);

if (renderedRowsChange) {
if (i == start)
firstRemovedRow_ = node->renderedRow();

removedHeight_ += node->renderedHeight();
}

node->removeFromParent();
}
}
} /* else:
children not loaded -- so we do not need to bother
*/
} else {
/*
* Only if the parent is in fact expanded, the spacer reduces
* in size
*/
if (isExpanded(parent)) {
RowSpacer *s = dynamic_cast<RowSpacer *>(parentWidget);

for (int i = start; i <= end; ++i) {
WModelIndex childIndex = model()->index(i, 0, parent);
int childHeight = subTreeHeight(childIndex);

if (renderedRowsChange) {
removedHeight_ += childHeight;

if (i == start)
firstRemovedRow_ = renderedRow(childIndex, s);
}
}
}
}
} else {
/*
parentWidget is 0: it means it is not even part of any spacer.
*/
}
}

shiftModelIndexes(parent, start, -count);
}

void WTreeView::modelRowsRemoved(const WModelIndex& parent,
int start, int end)
{
int count = end - start + 1;

if (renderState_ != RenderState::NeedRerender &&
renderState_ != RenderState::NeedRerenderData) {
WWidget *parentWidget = widgetForIndex(parent);

if (parentWidget) {
WTreeViewNode *parentNode = dynamic_cast<WTreeViewNode *>(parentWidget);

if (parentNode) {
if (parentNode->childrenLoaded()) {
parentNode->normalizeSpacers();
parentNode->adjustChildrenHeight(-removedHeight_);
parentNode->shiftModelIndexes(start, -count);

// Update graphics for last node in parent, if we are removing rows
// at the back. This is not affected by widgetForModelRow() returning
// accurate information of rows just deleted and indexes not yet
// shifted
if (end >= model()->rowCount(parent) && start >= 1) {
WTreeViewNode *n = dynamic_cast<WTreeViewNode *>
(parentNode->widgetForModelRow(start - 1));

if (n)
n->updateGraphics(true, !model()->hasChildren(n->modelIndex()));
}
} /* else:
children not loaded -- so we do not need to bother
*/

// Update graphics for parent when all rows have been removed
if (model()->rowCount(parent) == 0 && count != 0)
parentNode->updateGraphics(parentNode->isLast(), true);
} else {
/*
* Only if the parent is in fact expanded, the spacer reduces
* in size
*/
if (isExpanded(parent)) {
RowSpacer *s = dynamic_cast<RowSpacer *>(parentWidget);
WTreeViewNode *node = s->node();
s->setRows(s->rows() - removedHeight_); // could delete s!
node->adjustChildrenHeight(-removedHeight_);
}
}
} else {
/*
parentWidget is 0: it means it is not even part of any spacer.
*/
}
}

if (renderState_ != RenderState::NeedRerender &&
renderState_ != RenderState::NeedRerenderData)
renderedRowsChanged(firstRemovedRow_, -removedHeight_);
}

void WTreeView::modelDataChanged(const WModelIndex& topLeft,
const WModelIndex& bottomRight)
{
if (renderState_ == RenderState::NeedRerender ||
renderState_ == RenderState::NeedRerenderData)
return;
WModelIndex parent = topLeft.parent();
WTreeViewNode *parentNode = nodeForIndex(parent);

if (parentNode && parentNode->childrenLoaded()) {
for (int r = topLeft.row(); r <= bottomRight.row(); ++r) {
WModelIndex index = model()->index(r, 0, parent);

WTreeViewNode *n = nodeForIndex(index);

if (n)
n->update(topLeft.column(), bottomRight.column());
}
}
}

WWidget *WTreeView::headerWidget(int column, bool contentsOnly)
{
WWidget *result = nullptr;

if (headers_ && headers_->count() > 0) {
if (column == 0)
result = headers_->widget(headers_->count() - 1);
else
result = headerRow()->widget(column - 1);
}

if (result && contentsOnly)
return result->find("contents");
else
return result;
}

WContainerWidget *WTreeView::headerRow()
{
WContainerWidget *row
= dynamic_cast<WContainerWidget *>(headers_->widget(0));
if (rowHeaderCount())
row = dynamic_cast<WContainerWidget *>(row->widget(0));
return row;
}

int WTreeView::renderedRow(const WModelIndex& index, WWidget *w,
int lowerBound, int upperBound)
{
WTreeViewNode *node = dynamic_cast<WTreeViewNode *>(w);

if (node)
return node->renderedRow(lowerBound, upperBound);
else {
RowSpacer *s = dynamic_cast<RowSpacer *>(w);

int result = s->renderedRow(0, upperBound);

if (result > upperBound)
return result;
else if (result + s->node()->renderedHeight() < lowerBound)
return result;
else
return result + getIndexRow(index, s->node()->modelIndex(),
lowerBound - result, upperBound - result);
}
}

// TF: This function returns the zero-based numerical index of the table row
// for 'child' under 'ancestor', given that the parent of 'child' is expanded and
// using 'ancestor' as the (invisible) root.
int WTreeView::getIndexRow(const WModelIndex& child,
const WModelIndex& ancestor,
int lowerBound, int upperBound) const
{
if (!child.isValid() || child == ancestor)
return 0;
else {
WModelIndex parent = child.parent();

int result = 0;
for (int r = 0; r < child.row(); ++r) {
result += subTreeHeight(model()->index(r, 0, parent), 0,
upperBound - result);
if (result >= upperBound)
return result;
}

// TF: Adjustment with the position of parent within its siblings,
// only if parent is not the (invisible) root...
// getIndexRow() will deliver strange results anyway, if the
// parent of the initial child was not expanded!
if ( parent != ancestor )
result += 1 + getIndexRow( parent, ancestor,
lowerBound - result, upperBound - result );
return result;
// return result + getIndexRow(parent, ancestor,
// lowerBound - result, upperBound - result);
}
}

int WTreeView::renderLowerBound() const
{
return firstRenderedRow_;
}

int WTreeView::renderUpperBound() const
{
return firstRenderedRow_ + validRowCount_;
}

void WTreeView::renderedRowsChanged(int row, int count)
{
if (count < 0
&& row - count >= firstRenderedRow_
&& row < firstRenderedRow_ + validRowCount_)
validRowCount_ += std::max(firstRenderedRow_ - row + count, count);

if (row < firstRenderedRow_)
firstRenderedRow_ += count;

scheduleRerender(RenderState::NeedAdjustViewPort);
}

void WTreeView::adjustToViewport(WTreeViewNode *changed)
{
//assert(rootNode_->rowCount() == 1);

firstRenderedRow_ = std::max(0, firstRenderedRow_);
validRowCount_
= std::max(0, std::min(validRowCount_,
rootNode_->renderedHeight() - firstRenderedRow_));

int viewportBottom = std::min(rootNode_->renderedHeight(),
viewportTop_ + viewportHeight_);
int lastValidRow = firstRenderedRow_ + validRowCount_;

bool renderMore =
(std::max(0,
viewportTop_ - viewportHeight_) < firstRenderedRow_)
|| (std::min(rootNode_->renderedHeight(),
viewportBottom + viewportHeight_) > lastValidRow);

bool pruneFirst = false;

//assert(rootNode_->rowCount() == 1);

if (renderMore) {
int newFirstRenderedRow = std::min(firstRenderedRow_,
calcOptimalFirstRenderedRow());
int newLastValidRow = std::max(lastValidRow,
std::min(rootNode_->renderedHeight(),
calcOptimalFirstRenderedRow()
+ calcOptimalRenderedRowCount()));
//assert(rootNode_->rowCount() == 1);

int newValidRowCount = newLastValidRow - newFirstRenderedRow;

int newRows = std::max(0, firstRenderedRow_ - newFirstRenderedRow)
+ std::max(0, newLastValidRow - lastValidRow);

const int pruneFactor
= WApplication::instance()->environment().ajax() ? 9 : 1;

if (nodeLoad_ + newRows > pruneFactor * viewportHeight_) {
pruneFirst = true;
} else
if (newFirstRenderedRow < firstRenderedRow_
|| newLastValidRow > lastValidRow) {
firstRenderedRow_ = newFirstRenderedRow;
validRowCount_ = newValidRowCount;
adjustRenderedNode(rootNode_, 0);
}
}

const int pruneFactor
= WApplication::instance()->environment().ajax() ? 5 : 1;

if (pruneFirst || nodeLoad_ > pruneFactor * viewportHeight_) {
firstRenderedRow_ = calcOptimalFirstRenderedRow();
validRowCount_ = calcOptimalRenderedRowCount();

pruneNodes(rootNode_, 0);

if (pruneFirst && nodeLoad_ < calcOptimalRenderedRowCount()) {
adjustRenderedNode(rootNode_, 0);
}
}

//assert(rootNode_->rowCount() == 1);
}

int WTreeView::adjustRenderedNode(WTreeViewNode *node, int theNodeRow)
{
//assert(rootNode_->rowCount() == 1);

WModelIndex index = node->modelIndex();

if (index != rootIndex())
++theNodeRow;

if (!isExpanded(index) && !node->childrenLoaded())
return theNodeRow;

int nodeRow = theNodeRow;

if (node->isAllSpacer()) {
if (nodeRow + node->childrenHeight() > firstRenderedRow_
&& nodeRow < firstRenderedRow_ + validRowCount_) {
// replace spacer by some nodes
int childCount = model()->rowCount(index);

bool firstNode = true;
int rowStubs = 0;

for (int i = 0; i < childCount; ++i) {
WModelIndex childIndex = model()->index(i, 0, index);

int childHeight = subTreeHeight(childIndex);

if (nodeRow <= firstRenderedRow_ + validRowCount_
&& nodeRow + childHeight > firstRenderedRow_) {
if (firstNode) {
firstNode = false;
node->setTopSpacerHeight(rowStubs);
rowStubs = 0;
}

// assert(rootNode_->rowCount() == 1);

WTreeViewNode *n = node->childContainer()->addWidget
(cpp14::make_unique<WTreeViewNode>
(this, childIndex, childHeight - 1, i == childCount - 1, node));

int nestedNodeRow = nodeRow;
nestedNodeRow = adjustRenderedNode(n, nestedNodeRow);
assert(nestedNodeRow == nodeRow + childHeight);
} else {
rowStubs += childHeight;
}
nodeRow += childHeight;
}
node->setBottomSpacerHeight(rowStubs);
} else
nodeRow += node->childrenHeight();
} else {
// get a reference to the first existing child, which we'll recursively
// adjust later
int topSpacerHeight = node->topSpacerHeight();
int nestedNodeRow = nodeRow + topSpacerHeight;
WTreeViewNode *child = node->nextChildNode(nullptr);

int childCount = model()->rowCount(index);
while (topSpacerHeight != 0
&& nodeRow + topSpacerHeight > firstRenderedRow_) {
// eat from top spacer and replace with actual nodes
WTreeViewNode *n
= dynamic_cast<WTreeViewNode *>(node->childContainer()->widget(1));

assert(n);

WModelIndex childIndex
= model()->index(n->modelIndex().row() - 1, 0, index);

assert(childIndex.isValid());

int childHeight = subTreeHeight(childIndex);

{
std::unique_ptr<WTreeViewNode> nn
(n = new WTreeViewNode(this, childIndex, childHeight - 1,
childIndex.row() == childCount - 1, node));
node->childContainer()->insertWidget(1, std::move(nn));
}

nestedNodeRow = nodeRow + topSpacerHeight - childHeight;
nestedNodeRow = adjustRenderedNode(n, nestedNodeRow);
assert(nestedNodeRow == nodeRow + topSpacerHeight);

topSpacerHeight -= childHeight;
node->addTopSpacerHeight(-childHeight);
}

for (; child; child=node->nextChildNode(child))
nestedNodeRow = adjustRenderedNode(child, nestedNodeRow);

int nch = node->childrenHeight();
int bottomSpacerStart = nch - node->bottomSpacerHeight();

while (node->bottomSpacerHeight() != 0
&& nodeRow + bottomSpacerStart
<= firstRenderedRow_ + validRowCount_){
// eat from bottom spacer and replace with actual nodes
int lastNodeIndex = node->childContainer()->count() - 2;
WTreeViewNode *n = dynamic_cast<WTreeViewNode *>
(node->childContainer()->widget(lastNodeIndex));

assert(n);

WModelIndex childIndex
= model()->index(n->modelIndex().row() + 1, 0, index);

assert (childIndex.isValid());

int childHeight = subTreeHeight(childIndex);

{
std::unique_ptr<WTreeViewNode> nn
(n = new WTreeViewNode(this, childIndex, childHeight - 1,
childIndex.row() == childCount - 1, node));
node->childContainer()->insertWidget(lastNodeIndex + 1, std::move(nn));
}

nestedNodeRow = nodeRow + bottomSpacerStart;
nestedNodeRow = adjustRenderedNode(n, nestedNodeRow);
assert(nestedNodeRow == nodeRow + bottomSpacerStart + childHeight);

node->addBottomSpacerHeight(-childHeight);
bottomSpacerStart += childHeight;
}

nodeRow += nch;
}

// assert(rootNode_->rowCount() == 1);

// if a node has children loaded but is not currently expanded, then still
// adjust it, but do not return the calculated nodeRow for it.
return isExpanded(index) ? nodeRow : theNodeRow;
}

int WTreeView::pruneNodes(WTreeViewNode *node, int nodeRow)
{
// remove unneeded nodes: nodes within collapsed tree nodes, and nodes
// beyond the optimal bounds
WModelIndex index = node->modelIndex();

++nodeRow;

if (isExpanded(index)) {
// prune away nodes until we are within the rendered region
nodeRow += node->topSpacerHeight();

bool done = false;
WTreeViewNode *c = nullptr;

for (; nodeRow < firstRenderedRow_; ) {
c = node->nextChildNode(nullptr);
if (!c) {
done = true;
break;
}

if (nodeRow + c->renderedHeight() < firstRenderedRow_) {
node->addTopSpacerHeight(c->renderedHeight());
nodeRow += c->renderedHeight();
c->removeFromParent();
c = nullptr;
} else {
nodeRow = pruneNodes(c, nodeRow);
break;
}
}

if (!done) {
for (; nodeRow <= firstRenderedRow_ + validRowCount_; ) {
c = node->nextChildNode(c);

if (!c) {
done = true;
break;
}

nodeRow = pruneNodes(c, nodeRow);
}
}

if (!done) {
c = node->nextChildNode(c);

if (c != nullptr) {
int i = node->childContainer()->indexOf(c);
int prunedHeight = 0;

while (c && i < node->childContainer()->count()) {
c = dynamic_cast<WTreeViewNode *> (node->childContainer()->widget(i));
if (c) {
prunedHeight += c->renderedHeight();
c->removeFromParent();
c = nullptr;
}
}

node->addBottomSpacerHeight(prunedHeight);
}
}

nodeRow += node->bottomSpacerHeight();

node->normalizeSpacers();

} else
if (node->childrenLoaded()) {
int prunedHeight = 0;
for (;;) {
WTreeViewNode *c = node->nextChildNode(nullptr);
if (!c)
break;

prunedHeight += c->renderedHeight();
c->removeFromParent();
c = nullptr;
}

node->addBottomSpacerHeight(prunedHeight);
node->normalizeSpacers();
}

return nodeRow;
}

int WTreeView::
shiftModelIndexes(const WModelIndex& parent, int start, int count,
const std::shared_ptr<WAbstractItemModel>& model,
WModelIndexSet& set)
{
/*
* handle the set of exanded model indexes:
* - collect indexes in the same parent at lower rows that need to
* be shifted
* - if deleting, delete indexes that are within the range of deleted
* rows
*/
std::vector<WModelIndex> toShift;
std::vector<WModelIndex> toErase;

for (WModelIndexSet::iterator it
= set.lower_bound(model->index(start, 0, parent)); it != set.end();) {
#ifndef WT_TARGET_JAVA
WModelIndexSet::iterator n = it;
++n;
#endif

WModelIndex i = *it;

WModelIndex p = i.parent();
if (p != parent && !WModelIndex::isAncestor(p, parent))
break;

if (p == parent) {
toShift.push_back(i);
toErase.push_back(i);
} else if (count < 0) {
// delete indexes that are about to be deleted, if they are within
// the range of deleted indexes
do {
if (p.parent() == parent
&& p.row() >= start
&& p.row() < start - count) {
toErase.push_back(i);
break;
} else
p = p.parent();
} while (p != parent);
}

#ifndef WT_TARGET_JAVA
it = n;
#endif
}

for (unsigned i = 0; i < toErase.size(); ++i)
set.erase(toErase[i]);

int removed = 0;
for (unsigned i = 0; i < toShift.size(); ++i) {
// for negative count: only reinsert model indexes that need
// not be removed (they are currently all removed)
if (toShift[i].row() + count >= start) {
WModelIndex newIndex = model->index(toShift[i].row() + count,
toShift[i].column(), parent);
set.insert(newIndex);
} else
++removed;
}

return removed;
}

void WTreeView::shiftModelIndexes(const WModelIndex& parent,
int start, int count)
{
shiftModelIndexes(parent, start, count, model(), expandedSet_);

int removed = shiftModelIndexes(parent, start, count, model(),
selectionModel()->selection_);

shiftEditorRows(parent, start, count, false);

if (removed)
selectionChanged().emit();
}

void WTreeView::modelLayoutAboutToBeChanged()
{
WModelIndex::encodeAsRawIndexes(expandedSet_);

WAbstractItemView::modelLayoutAboutToBeChanged();
}

void WTreeView::modelLayoutChanged()
{
WAbstractItemView::modelLayoutChanged();

expandedSet_ = WModelIndex::decodeFromRawIndexes(expandedSet_);

renderedNodes_.clear();

pageChanged().emit();
}

void WTreeView::addRenderedNode(WTreeViewNode *node)
{
renderedNodes_[node->modelIndex()] = node;
++nodeLoad_;
renderedNodesAdded_ = true;
}

void WTreeView::removeRenderedNode(WTreeViewNode *node)
{
renderedNodes_.erase(node->modelIndex());
--nodeLoad_;
}

bool WTreeView::internalSelect(const WModelIndex& index, SelectionFlag option)
{
if (selectionBehavior() == SelectionBehavior::Rows &&
index.column() != 0)
return
internalSelect(model()->index(index.row(), 0, index.parent()), option);

if (WAbstractItemView::internalSelect(index, option)) {
WTreeViewNode *node = nodeForIndex(index);
if (node)
node->renderSelected(isSelected(index), index.column());

return true;
} else
return false;
}

WTreeViewNode *WTreeView::nodeForIndex(const WModelIndex& index) const
{
if (index == rootIndex())
return rootNode_;
else {
WModelIndex column0Index = index.column() == 0 ? index : model()->index(index.row(), 0, index.parent());
NodeMap::const_iterator i = renderedNodes_.find(column0Index);
return i != renderedNodes_.end() ? i->second : nullptr;
}
}

void WTreeView::selectRange(const WModelIndex& first, const WModelIndex& last)
{
WModelIndex index = first;
for (;;) {
for (int c = first.column(); c <= last.column(); ++c) {
WModelIndex ic = model()->index(index.row(), c, index.parent());
internalSelect(ic, SelectionFlag::Select);

if (ic == last)
return;
}

WModelIndex indexc0
= index.column() == 0 ? index
: model()->index(index.row(), 0, index.parent());

if (isExpanded(indexc0) && model()->hasChildren(indexc0))
index = model()->index(0, first.column(), indexc0);
else {
for (;;) {
// next row in parent, if one is available
WModelIndex parent = index.parent();
if (index.row() + 1 < model()->rowCount(parent)) {
index = model()->index(index.row() + 1, first.column(), parent);
break;
} else
// otherwise go up one level
index = index.parent();
}
}
}
}

WAbstractItemView::ColumnInfo WTreeView::createColumnInfo(int column) const
{
ColumnInfo ci = WAbstractItemView::createColumnInfo(column);

if (column == 0) {
// column 0 needs width auto, so we override the ci.styleRule with
// a more specific rule. We also set the correct overflow attributes

ci.width = WLength::Auto;
ci.styleRule->templateWidget()->resize(WLength::Auto, WLength::Auto);

if (c0StyleRule_) {
WCssStyleSheet& styleSheet = wApp->styleSheet();
c0StyleRule_->setSelector("#" + id() + " li ." + ci.styleClass());
styleSheet.addRule(styleSheet.removeRule(c0StyleRule_)); // needed on rerender
}
}

return ci;
}

void WTreeView::setCurrentPage(int page)
{
viewportTop_ = page * viewportHeight_;

contents_->setOffsets(-viewportTop_ * rowHeight().toPixels(), Side::Top);

pageChanged().emit();

scheduleRerender(RenderState::NeedAdjustViewPort);
}

int WTreeView::currentPage() const
{
return viewportTop_ / viewportHeight_;
}

int WTreeView::pageCount() const
{
if (rootNode_) {
return (rootNode_->renderedHeight() - 1) / viewportHeight_ + 1;
} else
return 1;
}

int WTreeView::pageSize() const
{
return viewportHeight_;
}

void WTreeView::scrollTo(const WModelIndex& index, ScrollHint hint)
{
// TF: Numeric index of table row for 'index', given that 'index' is visible,
// i.e. all of its parents are expanded.
// (This should not be increased by 1! s. getIndexRow())
int row = getIndexRow(index, rootIndex(), 0,
std::numeric_limits<int>::max());
// int row = getIndexRow(index, rootIndex(), 0,
// std::numeric_limits<int>::max()) + 1;

WApplication *app = WApplication::instance();

if (app->environment().ajax()) {
if (viewportHeight_ != UNKNOWN_VIEWPORT_HEIGHT) {
// TF: If 'EnsureVisible' then scroll to bottom, if 'row' is below
// the bottom visible entry, and scroll to top, if 'row' is above
// the first visible entry (minimal scrolling).
if (hint == ScrollHint::EnsureVisible) {
if (viewportTop_ + viewportHeight_ <= row)
hint = ScrollHint::PositionAtBottom;
else if (row < viewportTop_)
hint = ScrollHint::PositionAtTop;
}
/*
if (hint == ScrollHint::EnsureVisible) {
if (viewportTop_ + viewportHeight_ < row)
hint = ScrollHint::PositionAtTop;
else if (row < viewportTop_)
hint = ScrollHint::PositionAtBottom;
}
*/

switch (hint) {
case ScrollHint::PositionAtTop:
viewportTop_ = row; break;
case ScrollHint::PositionAtBottom:
viewportTop_ = row - viewportHeight_ + 1; break;
case ScrollHint::PositionAtCenter:
viewportTop_ = row - viewportHeight_/2 + 1; break;
default:
break;
}

if (hint != ScrollHint::EnsureVisible) {
scheduleRerender(RenderState::NeedAdjustViewPort);
}
}

WStringStream s;

s << "setTimeout(function() { jQuery.data(" << jsRef()
<< ", 'obj').scrollTo(-1, "
<< row << "," << static_cast<int>(rowHeight().toPixels())
<< "," << (int)hint << ");});";

doJavaScript(s.str());
} else
setCurrentPage(row / pageSize());
}

EventSignal<WScrollEvent>& WTreeView::scrolled(){
if (wApp->environment().ajax() && contentsContainer_ != nullptr)
return contentsContainer_->scrolled();

throw WException("Scrolled signal existes only with ajax.");
}
}

#endif // DOXYGEN_ONLY
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