... which is similar to the TRANSFORM_GRID controller, supporting
multiple transformation matrices.
Implement the TRANSFORM_GRIDS controller in GimpFilterTool, using
the new GimpToolWidgetGroup to display multiple transform grids.
(cherry picked from commit 5e953ece85)
... which allows ops to create a transform-grid widget, similar to
the unified-transform tool, which can be used to control a
transformation matrix.
Implement the transform-grid controller in GimpFilterTool.
Allow propgui constructors to specify an (optional) callback function
when creating pickers, to be called when a color/coordinate is picked,
similarly to controller callbacks.
Implement picker callback support in GimpFilterTool. When the active
picker has an associated callback function, call it instead of the
class's color_picked() function.
Add lots of "#include <gegl.h>" to .c files that miss it, which is
now necessary, since this commit adds a Babl* parameter in
propgui-types.h.
Add parameters, controlling the behavior and appearance of sliders,
to GimpControllerSlider. The macro GIMP_CONTROLLER_SLIDER_DEFAULT
expands to a nonmodifiable lvalue of type GimpControllerSlider,
whose members are initialized with the most common default values.
Handle the new parameters in GimpToolLine. A slider using the new
"autohide" mode is only visible when selected, or when the cursor
is close enough to the line, between the slider's min and max
values, and no other handle is grabbed or hovered-over.
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.
