A view class that displays a model as a tree or tree table. More...
#include <Wt/WTreeView>
Public Member Functions | |
WTreeView (WContainerWidget *parent=0) | |
Creates a new tree view. | |
~WTreeView () | |
Destructor. | |
void | setRootIndex (const WModelIndex &rootIndex) |
Sets the root index. | |
const WModelIndex & | rootIndex () const |
Returns the root index. | |
void | setColumnFormat (int column, const WString &format) |
Sets the column format string (deprecated). | |
WString | columnFormat (int column) const |
Returns the column format string (deprecated). | |
void | setExpanded (const WModelIndex &, bool expanded) |
Expands or collapses a node. | |
bool | isExpanded (const WModelIndex &index) const |
Returns whether a node is expanded. | |
void | collapse (const WModelIndex &index) |
Collapses a node. | |
void | expand (const WModelIndex &index) |
Expands a node. | |
void | expandToDepth (int depth) |
Expands all nodes to a depth. | |
virtual void | setAlternatingRowColors (bool enable) |
Sets if alternating row colors are to be used. Configure whether rows get an alternating background color. These are implemented by using a background image on the root node, like: | |
virtual bool | alternatingRowColors () const |
Returns whether alternating row colors are used. | |
void | setRootIsDecorated (bool show) |
Sets whether toplevel items are decorated. | |
bool | rootIsDecorated () const |
Returns whether toplevel items are decorated. | |
void | setColumn1Fixed (bool enable) |
Configures whether horizontal scrolling includes the first column. | |
bool | column1Fixed () const |
Returns whether horizontal scrolling includes the first column. | |
virtual void | resize (const WLength &width, const WLength &height) |
Resizes the widget. | |
Signal< WModelIndex > & | collapsed () |
Signal emitted when a node is collapsed. | |
Signal< WModelIndex > & | expanded () |
Signal emitted when a node is expanded. | |
virtual void | setModel (WAbstractItemModel *model) |
Sets the model. | |
virtual void | setColumnWidth (int column, const WLength &width) |
Sets the column width. | |
virtual WLength | columnWidth (int column) const |
Returns the column width. | |
virtual void | setRowHeight (const WLength &rowHeight) |
Sets the row height. | |
virtual void | setHeaderHeight (const WLength &height, bool multiLine=false) |
Sets the header height. | |
virtual void | setColumnAlignment (int column, AlignmentFlag alignment) |
Sets the content alignment for a column. | |
virtual AlignmentFlag | columnAlignment (int column) const |
Returns the content alignment for a column. | |
virtual void | setHeaderAlignment (int column, AlignmentFlag alignment) |
Sets the header alignment for a column. | |
virtual AlignmentFlag | headerAlignment (int column) const |
Returns the header alignment for a column. | |
virtual void | setColumnBorder (const WColor &color) |
Sets the column border color. | |
Protected Member Functions | |
virtual void | enableAjax () |
Progresses to an Ajax-enabled widget. |
A view class that displays a model as a tree or tree table.
The view displays data from a WAbstractItemModel in a tree or tree table. It provides incremental rendering, allowing the display of data models of any size efficiently, without excessive use of client- or serverside resources. Data of all predefined roles is displayed (see also ItemDataRole), including text, icons, checkboxes, and tooltips .
By default, all but the first columns are given a width of 150px, and the first column takes the remaining size. Note that this may have as consequence that the first column's size is reduced to 0. Column widths of all columns, including the first column, can be set through the API method setColumnWidth(), and also by the user using handles provided in the header.
Optionally, the treeview may be configured so that the first column is always visible while scrolling through the other columns, which may be convenient if you wish to display a model with many columns. Use setColumn1Fixed() to enable this behaviour.
If the model supports sorting (WAbstractItemModel::sort()), such as the WStandardItemModel, then you can enable sorting buttons in the header, using setSortingEnabled().
You can allow selection on row or item level (using setSelectionBehavior()), and selection of single or multiple items (using setSelectionMode()), and listen for changes in the selection using the selectionChanged() signal.
You may enable drag & drop support for this view, whith awareness of the items in the model. When enabling dragging (see setDragEnabled()), the current selection may be dragged, but only when all items in the selection indicate support for dragging (controlled by the ItemIsDragEnabled flag), and if the model indicates a mime-type (controlled by WAbstractItemModel::mimeType()). Likewise, by enabling support for dropping (see setDropsEnabled()), the treeview may receive a drop event on a particular item, at least if the item indicates support for drops (controlled by the ItemIsDropEnabled flag).
You may also react to mouse click events on any item, by connecting to one of the clicked() or doubleClicked() signals.
Usage example:
// WTreeView will display the data of a model Wt::WAbstractItemModel *model = ... // Create the WTreeView Wt::WTreeView *gitView = new Wt::WTreeView(); gitView->resize(300, Wt::WLength::Auto); gitView->setSortingEnabled(false); gitView->setModel(model); gitView->setSelectionMode(SingleSelection);
The treeview is styled by the current CSS theme. The look can be overridden using the Wt-treeview
CSS class and the following selectors.
Selectors that apply to the header:
.Wt-treeview .Wt-headerdiv : header (background) .Wt-treeview .Wt-header .Wt-label : header label .Wt-treeview .Wt-tv-rh : column resize handle .Wt-treeview .Wt-tv-sh-none : column sort handle, no sorting .Wt-treeview .Wt-tv-sh-up : column sort handle, sort up .Wt-treeview .Wt-tv-sh-down : column sort handle, sort down
Selectors that apply to the tree decoration:
.Wt-treeview .Wt-trunk : vertical line, trunk .Wt-treeview .Wt-end : vertical line, last item .Wt-treeview .Wt-collapse : collapse icon .Wt-treeview .Wt-expand : expand icon .Wt-treeview .Wt-noexpand : leaf icon
Selectors that apply to the table contents:
.Wt-treeview .Wt-spacer : spacer for non-loaded content .Wt-treeview .Wt-selected : selected item .Wt-treeview .Wt-drop-site : possible drop site
Selectors that apply to the table borders (which must be 1 pixel wide)
.Wt-treeview .Wt-tv-row .Wt-tv-c : border-right property of cells .Wt-treeview .Wt-header .Wt-tv-row, .Wt-treeview .Wt-tv-node .Wt-tv-row : border-left property of cells
A snapshot of the WTreeView:
WTreeView example (default)
WTreeView example (polished)
virtual bool Wt::WTreeView::alternatingRowColors | ( | ) | const [inline, virtual] |
Returns whether alternating row colors are used.
Implements Wt::WAbstractItemView.
void Wt::WTreeView::collapse | ( | const WModelIndex & | index ) |
Collapses a node.
Signal<WModelIndex>& Wt::WTreeView::collapsed | ( | ) | [inline] |
Signal emitted when a node is collapsed.
bool Wt::WTreeView::column1Fixed | ( | ) | const [inline] |
Returns whether horizontal scrolling includes the first column.
virtual AlignmentFlag Wt::WTreeView::columnAlignment | ( | int | column ) | const [virtual] |
Returns the content alignment for a column.
Implements Wt::WAbstractItemView.
WString Wt::WTreeView::columnFormat | ( | int | column ) | const |
Returns the column format string (deprecated).
virtual WLength Wt::WTreeView::columnWidth | ( | int | column ) | const [virtual] |
virtual void Wt::WTreeView::enableAjax | ( | ) | [protected, virtual] |
Progresses to an Ajax-enabled widget.
This method is called when the progressive bootstrap method is used, and support for AJAX has been detected. The default behavior will upgrade the widget's event handling to use AJAX instead of full page reloads, and propagate the call to its children.
You may want to reimplement this method if you want to make changes to widget when AJAX is enabled. You should always call the base implementation.
Reimplemented from Wt::WCompositeWidget.
void Wt::WTreeView::expand | ( | const WModelIndex & | index ) |
Expands a node.
Signal<WModelIndex>& Wt::WTreeView::expanded | ( | ) | [inline] |
Signal emitted when a node is expanded.
void Wt::WTreeView::expandToDepth | ( | int | depth ) |
Expands all nodes to a depth.
Expands all nodes to the given depth
. A depth of 1 corresponds to the top level nodes.
virtual AlignmentFlag Wt::WTreeView::headerAlignment | ( | int | column ) | const [virtual] |
Returns the header alignment for a column.
Implements Wt::WAbstractItemView.
bool Wt::WTreeView::isExpanded | ( | const WModelIndex & | index ) | const |
Returns whether a node is expanded.
Resizes the widget.
Specify a new size for this widget, by specifying width and height. By default a widget has automatic width and height, see WLength::isAuto().
This applies to CSS-based layout, and only block widgets can be given a size reliably.
When inserted in a layout manager, the widget may be informed about its current size using setLayoutSizeAware(). If you have defined a "wtResize()" JavaScript method for the widget, then this method will also be called. operation.
Reimplemented from Wt::WCompositeWidget.
const WModelIndex& Wt::WTreeView::rootIndex | ( | ) | const [inline] |
Returns the root index.
bool Wt::WTreeView::rootIsDecorated | ( | ) | const [inline] |
Returns whether toplevel items are decorated.
virtual void Wt::WTreeView::setAlternatingRowColors | ( | bool | enable ) | [virtual] |
Sets if alternating row colors are to be used. Configure whether rows get an alternating background color. These are implemented by using a background image on the root node, like:
Sample image use for alternating row colors
The image that is used is resourcesURL"/stripes/stripe-<i>n</i>px.gif", where n
is the row height. In the resource folder are images pregenerated for one color and row sizes from 10 to 30px.
The default value is false
.
Implements Wt::WAbstractItemView.
void Wt::WTreeView::setColumn1Fixed | ( | bool | enable ) |
Configures whether horizontal scrolling includes the first column.
To display a model with many columns, this option allows you to keep the first column fixed while scrolling through the other columns of the model.
The default value is false
.
enable
= true
is supported. virtual void Wt::WTreeView::setColumnAlignment | ( | int | column, |
AlignmentFlag | alignment | ||
) | [virtual] |
Sets the content alignment for a column.
The default value is AlignLeft.
Implements Wt::WAbstractItemView.
virtual void Wt::WTreeView::setColumnBorder | ( | const WColor & | color ) | [virtual] |
void Wt::WTreeView::setColumnFormat | ( | int | column, |
const WString & | format | ||
) |
Sets the column format string (deprecated).
The DisplayRole data for that column is converted to a string using asString(), with the given format.
The default value is "".
virtual void Wt::WTreeView::setColumnWidth | ( | int | column, |
const WLength & | width | ||
) | [virtual] |
Sets the column width.
For a model with columnCount() == N
, the initial width of columns 1..N
is set to 150 pixels, and column 0 will take all remaining space.
Implements Wt::WAbstractItemView.
void Wt::WTreeView::setExpanded | ( | const WModelIndex & | , |
bool | expanded | ||
) |
Expands or collapses a node.
virtual void Wt::WTreeView::setHeaderAlignment | ( | int | column, |
AlignmentFlag | alignment | ||
) | [virtual] |
Sets the header alignment for a column.
The default value is AlignLeft.
Implements Wt::WAbstractItemView.
virtual void Wt::WTreeView::setHeaderHeight | ( | const WLength & | height, |
bool | multiLine = false |
||
) | [virtual] |
Sets the header height.
Use this method to change the header height. You may also enable the use of multi-line headers. By default, the header text is a single line, that is centered vertically.
The default value is 20 pixels.
Implements Wt::WAbstractItemView.
virtual void Wt::WTreeView::setModel | ( | WAbstractItemModel * | model ) | [virtual] |
Sets the model.
The view will render the data in the given model
. Changes to the model are reflected in the view.
The initial model is 0
.
Ownership of the model is not transferred (and thus the previously set model is not deleted).
Reimplemented from Wt::WAbstractItemView.
void Wt::WTreeView::setRootIndex | ( | const WModelIndex & | rootIndex ) |
Sets the root index.
The root index is the model index that is considered the root node. This node itself is not rendered, but all its children are the top level nodes.
The default value is WModelIndex(), corresponding to the invisible root.
void Wt::WTreeView::setRootIsDecorated | ( | bool | show ) |
Sets whether toplevel items are decorated.
By default, top level nodes have expand/collapse and other lines to display their linkage and offspring, like any node.
By setting show
to false
, you can hide these decorations for root nodes, and in this way mimic a plain list.
virtual void Wt::WTreeView::setRowHeight | ( | const WLength & | rowHeight ) | [virtual] |
Sets the row height.
The view assumes that all rows are of the same height. Use this method to set the height.
The default value is 20 pixels.
Implements Wt::WAbstractItemView.