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The C++Builder IDE Explored: Projects and Forms
In many cases, the property editor for the property contains a list of items from which you
can choose. Properties that have an enumeration or boolean value as their base data type fall
into this category. When you click on the Value column with this type of property editor,
you will see a drop-down button on the right side of the Value column. Clicking this button
will display the list of possible values.
TIP
If you double-click the Value column for this type of property, the
property editor will cycle through the possible choices. To quickly
change a bool property, for instance, simply double-click its value.
Because the only choices are true and false double-clicking the value
has the effect of toggling the property’s value.
If you look closely at the Object Inspector, you will see that some properties have a plus sign
preceding the property name. Properties that are sets and properties that are objects both have
the plus sign in front of their names. The plus sign indicates that the property node can be
expanded to show the set or, in the case of properties that are objects, the properties of that
object. To expand a node, double-click on the Property column for that property (on the
property name) or choose Expand from the Object Inspector speed menu. To collapse the
node, double-click on it again or choose Collapse from the Object Inspector speed menu.
To see an example of a set, choose a form and then double-click on the BorderIcons property.
The node expands and you see four boolean members of the set. You can turn on or off any
of the four members as needed.
In the case of properties that are objects (instances of a VCL class), you have two choices in
editing the property. First, you can click on the Value column for the property and then click
the button to the right side of the value. This button is indicated by an ellipsis (…) on its face.
Clicking this button will invoke the property editor for that particular control. For example,
click on the Font property and then click the ellipsis button. The Choose Font dialog box is
displayed so that you can select the font. The second way you can edit this type of property
is by expanding the property node. The property’s properties (yes, it’s true) will be displayed,
and you can edit them just like any other property. Again, locate the Font property and
double-click on it. The TFont properties will be displayed. You can now modify the font’s
Height, Color, or Name properties.
For some properties you can use only the ellipsis button as a means of editing the property.
Earlier you used the Image component to select an icon for the Multiple program’s About box.
As you found out then, the Image component’s Picture property can be changed only by
invoking that property’s property editor. In that case, the property editor is the C++Builder
Image Editor.
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