DragAndDrop1
Low-level drag and drop operation
main.cpp
#include <CtrlLib/CtrlLib.h>
using namespace Upp;
struct MyAppData {
String text;
Color color;
};
struct MyApp : TopWindow {
Point pos;
MyAppData data;
Point dragpos;
virtual void CancelMode();
virtual void Paint(Draw& w);
virtual void DragAndDrop(Point p, PasteClip& clip);
virtual void DragLeave();
virtual void LeftDrag(Point p, dword keyflags);
MyApp();
};
void MyApp::CancelMode()
{
dragpos = Null;
Refresh();
}
void MyApp::DragAndDrop(Point p, PasteClip& clip)
{
if(clip.Accept("MyAppData")) {
String bin = clip;
if(bin.GetLength() > sizeof(Color)) { // prudent check
pos = p;
memcpy(&data.color, ~bin, sizeof(Color));
data.text = bin.Mid(sizeof(Color));
}
Refresh();
}
if(AcceptText(clip)) {
pos = p;
data.text = GetString(clip);
}
dragpos = clip.IsAccepted() ? p : Null;
Refresh();
}
void MyApp::DragLeave()
{
dragpos = Null;
Refresh();
}
void MyApp::LeftDrag(Point p, dword keyflags)
{
String bin;
bin.Cat((byte *)&data.color, sizeof(data.color));
bin.Cat(data.text);
VectorMap<String, ClipData> d;
d.Add("MyAppData", bin);
Append(d, data.text);
Size sz(128, 64);
ImageDraw iw(sz);
iw.DrawRect(sz, Black());
iw.Alpha().DrawRect(sz, Black());
iw.Alpha().DrawText(0, 0, data.text, Courier(14), White());
DoDragAndDrop(d, iw);
}
void MyApp::Paint(Draw& w)
{
w.DrawRect(GetSize(), SColorPaper());
w.DrawText(pos.x, pos.y, data.text, StdFont(), data.color);
if(!IsNull(dragpos))
w.DrawRect(RectC(dragpos.x - 1, dragpos.y - 1, 3, 3), LtBlue);
}
MyApp::MyApp()
{
data.text = FormatIntRoman(Random(2000));
data.color = Color(Random() & 127, Random() & 127, Random() & 127);
pos = Point(10, 10);
SetRect(0, 0, 500, 100);
dragpos = Null;
}
GUI_APP_MAIN
{
MyApp().Run();
}
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