TCustomTreeView.DoPaintNode

Renders the specified tree node to the canvas for the control.

Declaration

Source position: comctrls.pp line 3588

Arguments

Description

DoPaintNode is a method used to render the tree node specified in Node to the Canvas for the control. DoPaintNode is called from the DoPaint method, and occurs for visible nodes processed in the method. No actions are performed in the method when the Node is not in the visible client area for the control.

DoPaintNode draws the elements which represent a given tree node, including:

• Text for the tree node (when it is not the EditingItem for the control).
• An Image or State Image for the node.
• Expand or Collapse indicators for the node.
• Background for the node using theme services or node state.
• An Insert mark for the initial child node in the tree hierarchy.
• Horizontal and vertical lines used to join nodes in the tree hierarchy.
• The Separator line drawn after a node.

The text color is determined using the Enabled properties in both the tree view control and the tree Node. When theme services are enabled in Options (using tvoThemedDraw), theme element details provide the color and font style for the enabled state. Otherwise, the color value in DisabledFontColor or Font is used.

DoPaintNode retrieves scaled image resolutions needed for the Images and StateImages in the control. The images sizes are determined by applying the scaling factor in Canvas to the current PixelsPerInch setting in Font.

Use of multi-stage custom drawing is supported. If event handlers are provided for the cdPrePaint and cdPostPaint stages, the CustomDraw and CustomDrawItem methods are used to render the node with the drawing state for the node.

See also