Convenient FreePascal classes for handling macOS gestures.
Currently only magnification gesture is implemented, but other ones can be implemented easily in a similar way.
Let's assume your scalable control has a Scale property and you want to allow
an end user to scale it by using typical trackpad gesture. Here is the code:
uses
Gestures;
type
TForm_Main = class(TForm)
private
Gesture: TMagnificationGesture;
InitialScale: Double;
end;
procedure TForm_Main.FormCreate(Sender: TObject);
begin
Gesture := TMagnificationGesture.Create(Self);
Gesture.Control := MyScalableControl;
Gesture.OnGesture := @MagnificationGestureGesture;
end;
procedure TForm_Main.MagnificationGestureGesture(Sender: TMagnificationGesture;
State: TGestureState; Magnification: Double);
begin
case State of
gsBegan:
InitialScale := MyScalableControl.Scale;
gsChanged:
if Magnification > 0 then
MyScalableControl.Scale := InitialScale * (1 + Magnification)
else
MyScalableControl.Scale := InitialScale / (1 - Magnification);
end;
end;This package is licensed under the MIT license.
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