// NewDragWindow, Copyright © 1990 Ricardo Batista

// This code gets installed during system startup by an INIT, the purpose is to

// replace the old DragWindow routine with our code so that a window is moved

// along with it's contents as supposed to moving around an outline only.

//

// This code is for MPW C 3.1, when compiled into a resource the SysHeap and

// Locked bits need to be set in the resource attributes.

//

// After compiling copy this resource into a file that includes DragW INIT

//

#include "Types.h"

#include "Windows.h"

// we accept the same parameters as DragWindow, called by all Mac applications

pascal void NewDragWindow(WindowPtr w, Point pt, Rect *bounds)

{

    Point OldPoint, NewPoint, OffsetPoint;

    short h, v;

    GrafPtr savePort;

    GetPort(&savePort);                             // save the current port

    SetPort(w);                                     // set coordinate system to window

    OldPoint = NewPoint = pt;                       // make local copies of current mouse

    OffsetPoint.h = w->portRect.left;               // stuff top-left of window in point

    OffsetPoint.v = w->portRect.top;

    LocalToGlobal(&OffsetPoint);                    // convert too global coordinates

    OffsetPoint.h = pt.h - OffsetPoint.h;           // this offset is from window to mouse

    OffsetPoint.v = pt.v - OffsetPoint.v;

    while (StillDown()) {                           // is mouse still down ?

        GetMouse(&NewPoint);

        LocalToGlobal(&NewPoint);                   // whe now ?

        if (PtInRect(NewPoint, bounds)) {           // respect application boundaries

            if ((NewPoint.h != OldPoint.h) || (NewPoint.v != OldPoint.v)) {

                h = NewPoint.h - OffsetPoint.h;     // calculate new position of window

                v = NewPoint.v - OffsetPoint.v;     // using the offset of mouse-window

                MoveWindow(w, h, v, false);         // just do it

                OldPoint = NewPoint;                // save new 'old' location

            }

        }

    }

    SetPort(savePort);                              // restore coordinate system

}