About Component Properties in the Property Inspector

A property is a named attribute of a class that can affect its appearance or its behavior. A property can be:

Readable: These properties have a "get" method, which enables you to read the property's value. If it is a Boolean property, it can also use "is" to read the value.
Writable: These properties have a "set" method, which enables the property's value to be changed.
Both readable and writable: These properties have both "get" and "set" methods.

About Property Values in the Property Inspector

Properties are attributes that define how a component appears and responds at runtime. In JDeveloper, you set a component's initial properties during design time, and your code can change those properties at runtime.

The Properties page in the Property Inspector displays the properties of the selected component(s) and is where you set the property values at design time for any component in your design. By setting properties at design time, you are defining the initial state of a component when the UI is instantiated at runtime.

Note:To modify the initial property values at runtime, you can put code in the body of the methods or event handlers which you can create on the Events page of the Property Inspector.

About Shared Properties for Multiple Components

When you display the Property Inspector with more than one component is selected in the Java Visual Editor, by default the Property Inspector displays all the properties of the selected components (the union). You can control whether to show all properties or only the properties shared among the objects (the intersection) by clicking the Union button on the Property Inspector toolbar:

Union button with a selected state (default "union" mode) displays all properties of the selected components
Union button with the unselected state ("intersection" mode) displays only the properties the selected components have in common

Despite the fact that you may have selected multiple components in the Java Visual Editor, the Property Inspector still only displays property values for one component at a time. When the properties are shared among the selected components, sometimes the values will be the same, and in other cases, the property values may differ among the components. The Property Inspector helps you to identify which shared properties have differing values by representing the value in italics.

When the values for shared properties differ among the selected components, the property value that is displayed always belongs to the anchor selection. The anchor selection is the one that appears with hollow selection handles in the Java Visual Editor. You may alter the anchor selection by holding down the Shift key and clicking one of the other currently selected components. Altering the anchor selection changes which components' properties are shown in the Inspector, as well as altering which component the Java Visual Editor context menu operations apply to (for example, the Align context menu item).

When you change any of the shared properties in the Property Inspector, the property value changes to the new value in all the selected components.