Inside Macintosh: Mac OS 8 Toolbox Reference /

Chapter 1 - Appearance Manager Reference / Appearance Manager Functions

Defining Your Own Menu Drawing Callback Functions /

MyMenuItemDrawingProc

NEW WITH THE APPEARANCE MANAGER

Draws a custom menu item that coordinates with the current theme.

The Appearance Manager declares the type for an application-defined menu item drawing function as follows:

typedef pascal void (*MenuItemDrawingProcPtr)(const Rect *inBounds, 
SInt16 inDepth, Boolean inIsColorDevice, SInt32 inUserData);

The Appearance Manager defines the data type MenuItemDrawingUPP to identify the universal procedure pointer for an application-defined menu item drawing function:

typedef UniversalProcPtr MenuItemDrawingUPP;

You typically use the NewMenuItemDrawingProc macro like this:

MenuItemDrawingUPP myMenuItemDrawingUPP;
myMenuItemDrawingUPP = NewMenuItemDrawingProc(MyMenuItemDrawingProc);

You typically use the CallMenuItemDrawingProc macro like this:

CallMenuItemDrawingProc(myMenuItemDrawingUPP, inBounds, inDepth, inIsColorDevice, inUserData);

Here's how to declare a custom menu item drawing function, if you were to name the function MyMenuItemDrawingProc:

pascal void (MyMenuItemDrawingProc)
                     (const Rect *inBounds,
                     SInt16 inDepth,
                     Boolean inIsColorDevice,
                     SInt32 inUserData);

inBounds

On input, a pointer to a rectangle in which you should draw your menu item content.

inDepth

The bit depth (in pixels) of the current graphics port.

inIsColorDevice

A Boolean value. Set to true to indicate that you are drawing on a color device. Set to false for a monochrome device.

inUserData

User data specifying how to draw the menu item content, passed in from the inUserData parameter of DrawThemeMenuItem.

DISCUSSION

Your menu item drawing function will be called clipped to the rectangle in which you are allowed to draw your content; do not draw outside this region. You should center your content vertically inside the content rectangle.

At the time your menu item drawing function is called, the foreground text color and mode is already set to draw in the specified state (enabled, selected, disabled) and correct color for the theme. You do not need to set the color unless you have special drawing needs.

IMPORTANT

You should not depend on the background color for your menu item, so you should not call the EraseRect function from your menu item drawing function.

SPECIAL CONSIDERATIONS

Make sure Appearance Manager 1.0.1 is present before calling your MyMenuItemDrawingProc function. See "Appearance Manager Gestalt Selector Constants" for details on how to determine if the Appearance Manager is present and what its version is, if so.