... which is emitted when a handle is single/double/tripple clicked.
The signal handler returns a boolean value. A return value of TRUE
stops further event processing, while a return value of FALSE allows
it.
The signal is emitted when a slider is dragged away from the line,
and will be removed when the button is released, and when the
slider is dragged back to the vicinity of the line, and won't be
removed. The last parameter of the signal is a boolean flag
differentiating between the two cases.
Note that a remove-slider signal may be emitted without a preceeding
prepare-to-remove-slider signal, however, is a prepare-to-remove-
slider signal is emitted with a TRUE last parameter, it must be
eventually followed by a remove-slider signal, or by another
prepare-to-remove-slider signal with a FALSE last parameter.
Add support for adding and removing sliders to/from a GimpToolLine,
using three new signals:
- can-add-slider: Takes a double argument in the range [0,1],
indicating a location along the line, and returns a boolean
value, indicating whether a slider can be added at that
location.
- add-slider: Takes a double argument in the range [0,1],
indicating a location along the line, for which can-add-slider
returned TRUE. In response, should add a new slider at that
location, and return its index, or a negative value if no
slider was added.
- remove-slider: Takes a slider index. In response, may remove
the slider.
On the UI side, when the cursor is close enough to the line, but
not within the hit area of an existing handle, GimpToolLine checks
if a slider can be added at the cursor position, using can-add-
slider. If a slider can be added, a dashed circle appears at the
cursor position along the line, indicating where a slider will be
added. The cursor is added by clicking, which emits an add-slider
signal; if the signal returns a slider index, the new slider is
selected, and can be subsequently dragged.
Removing a slider is done by either selecting the slider and
pressing backspace (or delete, although we don't actually forward
it to the tool atm,) or by "tearing" the slider: when dragging
the slider, if the cursor is far enough from the liner, a dashed
circle appears around the slider, and releasing the mouse removes
the slider.
En route to on-canvas gradient editing, add support for persistent
handle selection to GimpToolLine (a handle being either an endpoint
or a slider). Handles are selected through clicking, however,
unlike before, the selection persists after the mouse is released.
A new "selection" property specifies the currently-selected handle
(who knows, maybe in the future we'll add multi-selection), and a
new "selection-changed" signal is emitted when the selection changes.
The visual feedback has been changed to better suit the new behavior,
and the behaviors yet to be added: The selected handle is marked
using highlighting; the highlighting doesn't change while hovering
over other handles. Only the hit-test circle is used as hover
indication, however, we use a fixed-size circle, and only show the
circle for the currently hovered-over handle -- no more trippy
expanding circles :)
A few minor changes along the way:
- The selected handle is now the (first) one that's closest to the
cursor, instead of the first one to pass hit-testing.
- We don't move the selectd handle upon button-press, only upon
motion, so that handles can be selected without moving them.
- Show a MOVE cursor modifier when hovering over a handle.
Add supprt for placing sliders on a GimpToolLine -- handles that can
be dragged over the line. The sliders are accesible through a new
"sliders" property, and via the gimp_tool_line_{get,set}_sliders()
functions.
Add a slider-line controller, which works like a line controller,
but whose callback also supplies/takes an array of sliders.
Note that the data type for individual sliders is called
GimpControllerSlider (in particular, it's not line specific), so
that we may use it with other controller/tool-widget types in the
future.