|
WSupported on Windows
|
|
|
|
.BUTTON name [, TEXT(button_text)|BITMAP(file)] – [, METHOD(method_name[, elb_name])] [, SELECT(character)]
Arguments
name
The name of the button (maximum 30 characters).
TEXT (button_text)
(optional) The text to display on the button face.
BITMAP (file)
(optional) The filename for a graphic to display on the button face. See Toolkit button graphics for supported formats.
METHOD (method_name[, elb_name])
(optional) Specify a method to invoke when the button is clicked; optionally include the name of the library for the method. If not specified, the button’s name is the menu entry signaled when the button is pressed.
SELECT (character)
(optional) The quick-select character for the button. If not passed or blank, the button will not have a quick-select character.
On Windows, you can use the .BUTTON command to add buttons to a window. The maximum number of buttons allowed in a window is 127.
When a window is being processed, its buttons are automatically enabled by default, and when a window is not being processed, its buttons are automatically disabled by default. However, note the following:
- Buttons that have been disabled (with %B_DISABLE) will not be automatically enabled, and buttons that have been enabled (with %B_ENABLE) will not be automatically disabled unless %B_ENABLE is used with the input_only argument set to true to restore the default behavior for the button. See %B_ENABLE for more information.
- To enable buttons on general windows, you must either use %B_ENABLE or process the window with T_VIEW or T_EDIT.
- For composite windows, C_PROCESS enables buttons for the composite container window and all enabled child windows and lists, even those that are not active. Note, however, that this is not the case when C_PROCESS is called for a composite window that’s part of another composite window. In this case, buttons will have already been enabled by the C_PROCESS call for the outer composite window. Additionally, when C_PROCESS returns, it disables buttons for the composite window and all child windows and lists—unless the C_PROCESS call is for a composite window that’s part of another composite window. If it is, buttons will be disabled when C_PROCESS returns for the outer composite window.
- For composite windows, buttons that are explicitly enabled with %B_ENABLE (without the input_only flag set true) remain enabled when composite window processing is finished.
The placement of the button is determined by the .BUTTON_SET command. If no .BUTTON_SET command is specified, the buttons are placed (in their defined order) at the bottom of the window, left-justified.
The order in which buttons are defined determines how they are added to the window tabbing order. Tab moves forward and Shift+Tab moves backward through the buttons as if they were fields in the input window.
Focus (display of the active item) is shown on the buttons as a thin dotted line around the text portion of the button. When focused, the button can be “pressed” using either the spacebar or the Enter key. Whether focused or not, any button can be selected (“pressed”) by clicking on it with the left mouse button.
If neither TEXT nor BITMAP is specified, the button name will be displayed on the button face.
If method_name is specified, it will be invoked when the button is clicked. The arguments passed to the method are the window ID, button name, and the 20 optional method data arguments passed to I_INPUT.
If a select character is specified, pressing Alt+character will have the effect of pressing the button. See the B_BUTTON Discussion.
The window will expand downward or to the right to accommodate the buttons. This expansion may cause your window to extend beyond the bottom or right side of your application window. Also, the button will be a standard size. Therefore, text that exceeds the size of the button will not be visible.
UI Toolkit buttons support the following graphics formats:
- BMP—Windows bitmap
- GIF—Graphics Interchange Format
- JPEG—Joint Photographic Experts Group (stored in JPEG File Interchange Format, JFIF)
- Exif—Exchangeable Image File
- PNG—Portable Network Graphics
- TIFF—Tag Image File Format
If an image is too large for the button face, the image will be cropped; Toolkit won’t scale the image to fit the button. If Toolkit can’t find the file, or if it isn’t one of the supported file types, Toolkit will leave the button face blank.
.BUTTON has no effect on applications running on Unix or OpenVMS. Script does, however, save button information on these platforms, so if the window is loaded on a Windows platform, the button will be displayed (assuming ISAM-compatible platforms).
See also
- .BUTTON_SET for more information about specifying the placement of button sets
- IB_BUTTON for more information about specifying buttons for an input window built at runtime
- B_BUTTON for more information about specifying buttons in a window or tab set
- L_BUTTON for more information about specifying buttons on a list
- %B_DISABLE and %B_ENABLE for more information about disabling and enabling buttons
Examples
This example displays an OK button that signals “I_OK,” a Cancel button that signals “O_ABANDON,” and a Help button that calls HELP_METHOD when pressed. The OK button has the quick-select character “K.” When Alt+K is pressed, a click of the OK button is simulated.
.button I_OK, text("OK"), select(K)
.button O_ABANDON, text("Cancel")
.button help, text("Help"), method("HELP_METHOD")
