Debug Utilities

A few utilities useful for debugging are available in the package ej.widget.util.debug of the widget library.

Print the Hierarchy of Widgets

The method HierarchyInspector.hierarchyToString(Widget) returns a String representing the hierarchy of a widget. In other words, it prints the widget and its children recursively in a tree format.

It may be used to analyse the content of a page and have a quick estimation of the number of widgets and the depth of the hierarchy.

For example:

Scroll
+--ScrollableList
|  +--Label
|  +--Dock
|  |  +--ImageWidget
|  |  +--Label
|  +--Label

Print the Path to a Widget

The method HierarchyInspector.pathToWidgetToString(Widget) returns a String representing the list of ancestors of the widget. For example: Desktop > Scroll > ScrollableList > Label.

It may be used to identify a widget in a trace.

It is also possible to choose the separator by using HierarchyInspector.pathToWidgetToString(Widget, char) method. For example: Desktop ; Scroll ; ScrollableList ; Label.

Count the Number of Widgets or Containers

The methods HierarchyInspector.countNumberOfWidgets(Widget) and HierarchyInspector.countNumberOfContainers(Widget) respectively count the number of widgets and containers in a hierarchy.

It may be used to evaluate the complexity of a hierarchy of widgets.

Count the Maximum Depth of a Hierarchy

The method HierarchyInspector.countMaxDepth(Widget) counts the maximum depth of a hierarchy. In other words, the depth of the widget with the biggest number of parents recursively.

It may be used to evaluate the complexity of a hierarchy of widgets.

Print the Bounds of a Widget

The method BoundsInspector.boundsToString(Widget) returns a String with the widget type and its bounds. The returned String contains:

• the simple name of the class of the widget,
• its position relative to its parent,
• its size,
• its absolute position.

For example: Label: 0,0 7x25 (absolute: 75,75)

Print the bounds of all the widgets in a hierarchy

The method BoundsInspector.boundsRecursiveToString(Widget) returns a String representing the type and bounds of each widget in the hierarchy of a widget.

For example:

Scroll: 0,0 480x272 (absolute: 0,0)
+--ScrollableList: 0,0 480x272 (absolute: 0,0)
|  +--Label: 0,0 480x50 (absolute: 0,0)
|  +--Dock: 0,50 480x50 (absolute: 0,50)
|  |  +--ImageWidget: 0,0 70x50 (absolute: 0,50)
|  |  +--Label: 70,0 202x50 (absolute: 70,50)
|  +--Label: 0,100 480x50 (absolute: 0,100)