Theme Engine Online Help

Topics

Topic	Description
Using TTeTheme	Generally the themes is a set of properties and methods with the help of which it is possible to find out the necessary parameters (such as fonts, colors and metrics), and to paint the components of the interface. ThemeEngine has an abstract base TTeTheme class, which contains all the necessary properties and methods for the correct use of the theme. In other words the programmer does not have to know which theme is active at the current moment, how to load, to change and at last how to paint different themes. ThemeEngine closes the details of realization of concrete themes, such as ThemeEngine themes, msstyles themes, the built-in themes. In other words it is impossible to find out directly what elements the theme consists of, in what format it is saved. The interaction process occurs via the TTeTheme base class. The global variable CurrentTheme points to the theme active at the current moment. Before using this variable it is necessary to make sure, whether it is possible to use it calling the special IsThemeAvailable(CurrentTheme) function. If this function returns true the active theme is available.
Using te_uxtheme	ThemeEngine emulates a well-described and understandable MS Theme API (uxtheme.dll) interface. If your application or components use MS Theme API for the correct display in Windows XP they can easily get ThemeEngine support, it is only necessary to add te_uxtheme in the module and then if the active theme is ThemeEngine, yours applications and the component will use it. Otherwise if the program is started in Windows XP and the visual styles are active, the uxtheme.dll library will be involved. The detailed MS Theme API documentation can be received here.
ThemeEngine messages	ThemeEngine provides one message for interaction of various components and the cursor itself. Each component which uses the themes is to process this message in order to display itself correctly and to change the necessary parameters and repaint at changing of the active theme. For your component to be able to receive ThemeEngine messages you are to register its AddThemeNotification procedure which is being used. The registration is usually made in the designer. It is necessary to call the RemoveThemeNotification procedure before the destruction of the component (usually in the destructor).