Adding support for middle, backward, and forward mouse buttons click events, adds config keys : "on-click-middle", "on-click-forward" and "on-click-backward"
Adding the key "format-alt-click" to choose what mouse clicks toggles the alternative format, when present. Possible values (in config): "click-right", "click-left", "click-middle", "click-forward", "click-backward". Other values have the same effect than "click-left". Previous behaviour was to toggle it whenever any click was registered and any click that was not handled by "on-click-right" or "on-click-left" occurred
This patch adds 3 new configuration options applicable for
subclasses of ALabel. The options can be used to execute
user defined code in response to the 3 mouse events:
* on-click: The left mouse button click
* on-scroll-up
* on-scroll-down
This patch also modifies the behaviour of the format-alt toggle
such that when the on-click event is configured, format-alt is
toggled on any mouse click other than left click. When on-click
is not defined, any mouse button would toggle format-alt.
Signed-off-by: Harish Krupo <harishkrupo@gmail.com>