Mouse event list

In this tutorial we wish to adopt the following behavior for ctedits that contain Exp trees:

• Clicking with the left button sets the current selection for editing purposes. Also, dragging the mouse outside the ctedit window with the left button depressed scrolls the ctedit.
• Clicking with the left button while holding the shift button copies the designated subtree (without setting the current selection) to the X selection buffer. Clicking with the middle button while holding the shift button replaces the designed subtree with the contents of the X selection buffer.
• Clicking with the middle button on a variable name highlights (with a special selection) all occurrences of the variable in all windows.
• Clicking with the right button pops up a menu that contains buttons to start interpretation and to clear the initial and final environment views.
• Typing ctrl-e enters in-line editing mode.

To achieve this behavior, we must specify an appropriate for any ctedit containing an Exp program. The following lines should be included in the file: contrib/Exp/syntax/Exp.rdb

Centaur.editor-Exp.mouseEventList:(\resbs
        (left . \{ctedit\}:current:auto-scroll) \resbs
        (left-shift .\{ctedit\}:current:xcopy) \resbs
        (middle-shift . \{ctedit\}:current:xchange) \resbs
        (middle . \{Exp\}:select-variable) \resbs
        (right . \{ctedit\}:popup) \resbs
        (ascii . \{ctedit\}:auto-menu:ascii))

All of the above callback packages except {Exp}:select-variable are predefined by Centaur. We explain the new package in section .

Example. To replace the current selection with a menu entry, click on the menu element with the left button. To set the current selection and simultaneously copy it to the X selection buffer, press the shift key and click with the left button. To replace the current selection with the contents of the X selection, use shift/middle button.

N.B. The preceding resources only apply to those editors named Exp. In section we show how to assign a name to any editor containing an Exp tree.

Finally, make sure you have correctly positioned the unix environment DISPLAY variable so that Centaur appears on the correct machine.