rsc3/doc-schelp/HelpSource/Classes/DragSink.schelp

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class:: DragSink
summary:: A simple drag-and-drop receiver.
categories:: GUI>Views
related:: Classes/DragBoth, Classes/DragSource
DESCRIPTION::
link::Classes/DragSource::, link::Classes/DragSink:: and link::Classes/DragBoth:: are a set of view classes intended as simple-to-use drag-and-drop sources and destinations. They are graphically represented as a simple rectangle, and their specialty is that they emphasis::do not require the Cmd/Ctrl key to be held down to initiate dragging::.
Akin to link::Classes/StaticText:: they can store arbitrary content in the link::Classes/StaticText#-object#-object:: variable, and display it using link::Classes/Object#-asString::. You can set the displayed text separately using link::Classes/StaticText#-string#-string::, and keep it independent of the content if you set link::Classes/StaticText#-setBoth#-setBoth:: to code::false::.
strong::DragSink::, specifically, strong::accepts any:: dropped data and stores it into the strong::-object:: variable, but allows strong::no dragging::.
See: link::Classes/View#Drag and drop:: for a general description of the drag and drop mechanism.
CLASSMETHODS::
PRIVATE:: key
INSTANCEMETHODS::
METHOD:: defaultCanReceiveDrag
RETURNS:: Always True.
METHOD:: defaultReceiveDrag
Sets the link::Classes/StaticText#-object#-object:: to the current drag data.
EXAMPLES::
code::
(
s.waitForBoot({ // only needed if you are using sound
w = Window.new.front;
// store various kinds of objects in the drag source
// a string source
a = DragSource(w, Rect(10, 10, 150, 20)).align_(\center);
a.object = "I am a string source";
// a Float source
b = DragSource(w, Rect(10, 40, 150, 20)).align_(\center);
b.object = 2.234;
// a Point source
c = DragSource(w, Rect(10, 70, 150, 20)).align_(\center);
c.object = Point(20, 30);
// A sound function source
// dragLabel_() is used for the label while dragging
d = DragSource(w, Rect(10, 100, 150, 20)).align_(\center);
d.object = { Synth(\default) };
d.dragLabel = " I am a sound function.\n My dragLabel_() is set \n to inform you about that ";
// A sound function source
// here the string label is independent of the content type (Function)
// dragLabel_() is used for the label while dragging
f = DragSource(w, Rect(10, 130, 150, 20)).align_(\center).setBoth_(false);
f.object = { { SinOsc.ar(440,0,0.4) }.play };
f.string = "My label is independent";
f.dragLabel = " My dragLabel_() says \n I am dragging a sound function ";
// receive anything
g = DragSink(w, Rect(170, 10, 200, 20)).align_(\center);
g.string = "receive anything, do nothing";
// receive only floats
g = DragSink(w, Rect(170, 40, 200, 20)).align_(\center);
g.string = "I only like floats";
g.canReceiveDragHandler = { View.currentDrag.isFloat };
// receive only numbers and points, and convert them to rects
h = DragSink(w, Rect(170, 70, 200, 20)).align_(\center);
h.string = "I convert to Rect";
h.canReceiveDragHandler = { View.currentDrag.isKindOf(Number) || View.currentDrag.isKindOf(Point) };
h.receiveDragHandler = { arg v; h.object = View.currentDrag.asRect };
// receive only functions, and try to play them
i = DragSink(w, Rect(170, 100, 200, 20)).align_(\center);
i.string = "I evaluate a (sound) function";
i.canReceiveDragHandler = { View.currentDrag.isKindOf(Function) };
i.receiveDragHandler = { arg v;
i.object = View.currentDrag.value;
i.string = "click here for silence";
i.background_(Color.red) };
i.mouseDownAction_({
i.object.free;
i.string = "I evaluate a (sound) function";
i.background_(Color.clear) });
StaticText(w, Rect(10, 200, 380, 50))
.stringColor_(Color.white)
.string_("Try dragging any item on the left -----> to any item on the right");
});
)
::