29.3 Toolbar Descriptor Format

The contents of a toolbar are specified using a toolbar descriptor. The format of a toolbar descriptor is a list of toolbar button descriptors. Each toolbar button descriptor is a vector in one of the following formats:

• [glyph-list function enabled-p help]
• [:style 2d-or-3d]
• [:style 2d-or-3d :size width-or-height]
• [:size width-or-height :style 2d-or-3d]

Optionally, one of the toolbar button descriptors may be nil instead of a vector; this signifies the division between the toolbar buttons that are to be displayed flush-left, and the buttons to be displayed flush-right.

The first vector format above specifies a normal toolbar button; the others specify blank areas in the toolbar.

For the first vector format:

• glyph-list should be a list of one to six glyphs (as created by make-glyph) or a symbol whose value is such a list. The first glyph, which must be provided, is the glyph used to display the toolbar button when it is in the “up” (not pressed) state. The optional second glyph is for displaying the button when it is in the “down” (pressed) state. The optional third glyph is for when the button is disabled. The last three glyphs are for displaying the button in the “up”, “down”, and “disabled” states, respectively, but are used when the user has called for captioned toolbar buttons (using toolbar-buttons-captioned-p). The function toolbar-make-button-list is useful in creating these glyph lists.
• Even if you do not provide separate down-state and disabled-state glyphs, the user will still get visual feedback to indicate which state the button is in. Buttons in the up-state are displayed with a shadowed border that gives a raised appearance to the button. Buttons in the down-state are displayed with shadows that give a recessed appearance. Buttons in the disabled state are displayed with no shadows, giving a 2-d effect.
• If some of the toolbar glyphs are not provided, they inherit as follows:

       UP:                up
       DOWN:              down -> up
       DISABLED:          disabled -> up
       CAP-UP:            cap-up -> up
       CAP-DOWN:          cap-down -> cap-up -> down -> up
       CAP-DISABLED:      cap-disabled -> cap-up -> disabled -> up
  

• The second element function is a function to be called when the toolbar button is activated (i.e. when the mouse is released over the toolbar button, if the press occurred in the toolbar). It can be any form accepted by call-interactively, since this is how it is invoked.
• The third element enabled-p specifies whether the toolbar button is enabled (disabled buttons do nothing when they are activated, and are displayed differently; see above). It should be either a boolean or a form that evaluates to a boolean.
• The fourth element help, if non-nil, should be a string. This string is displayed in the echo area when the mouse passes over the toolbar button.

For the other vector formats (specifying blank areas of the toolbar):

• 2d-or-3d should be one of the symbols 2d or 3d, indicating whether the area is displayed with shadows (giving it a raised, 3-d appearance) or without shadows (giving it a flat appearance).
• width-or-height specifies the length, in pixels, of the blank area. If omitted, it defaults to a device-specific value (8 pixels for X devices).

Function: toolbar-make-button-list up &optional down disabled cap-up cap-down cap-disabled

This function calls make-glyph on each arg and returns a list of the results. This is useful for setting the first argument of a toolbar button descriptor (typically, the result of this function is assigned to a symbol, which is specified as the first argument of the toolbar button descriptor).

Function: check-toolbar-button-syntax button &optional noerror

Verify the syntax of entry button in a toolbar description list. If you want to verify the syntax of a toolbar description list as a whole, use check-valid-instantiator with a specifier type of toolbar.