Allow confining the pointer to part of the window during drags. Actually

we aren't acting on this for any current drag types, but if we need to do
so in the future (eg. frame resizing), this is the code to do it.  The trap
lasts 10 IntuiTicks so is re-asserted on every mouse move when an active
drag is in effect.  Drag type must be set to GDRAGGING_NONE to clear.

svn path=/trunk/netsurf/; revision=13401

amiga/gui.c

@@ -1090,6 +1090,54 @@ void ami_gui_scroll_internal(struct gui_window_2 *gwin, int xs, int ys)
 	}
 }
 
+struct IBox *ami_ns_rect_to_ibox(struct gui_window_2 *gwin, const struct rect *rect)
+{
+	struct IBox *bbox, *ibox;
+
+	ibox = AllocVec(sizeof(struct IBox), MEMF_CLEAR | MEMF_PRIVATE);
+	if(ibox == NULL) return NULL;
+
+	GetAttr(SPACE_AreaBox, (Object *)gwin->objects[GID_BROWSER], (ULONG *)&bbox);
+
+	ibox->Left = gwin->win->MouseX + (rect->x0 * gwin->bw->scale);
+	ibox->Top = gwin->win->MouseY + (rect->y0 * gwin->bw->scale);
+
+	ibox->Width = (rect->x1 - rect->x0) * gwin->bw->scale;
+	ibox->Height = (rect->y1 - rect->y0) * gwin->bw->scale;
+
+	if(ibox->Left < bbox->Left) ibox->Left = bbox->Left;
+	if(ibox->Top < bbox->Top) ibox->Top = bbox->Top;
+
+	if((ibox->Left > (bbox->Left + bbox->Width)) ||
+		(ibox->Top > (bbox->Top + bbox->Height)) ||
+		(ibox->Width < 0) || (ibox->Height < 0))
+	{
+		FreeVec(ibox);
+		return NULL;
+	}
+
+	return ibox;	
+}
+
+void ami_gui_trap_mouse(struct gui_window_2 *gwin)
+{
+	switch(gwin->drag_op)
+	{
+		case GDRAGGING_NONE:
+		case GDRAGGING_SCROLLBAR:
+		case GDRAGGING_OTHER:
+		break;
+
+		default:
+			if(gwin->ptr_lock)
+			{
+				SetWindowAttrs(gwin->win, WA_GrabFocus, 10,
+					WA_MouseLimits, gwin->ptr_lock, TAG_DONE);
+			}
+		break;
+	}
+}
+
 void ami_handle_msg(void)
 {
 	struct IntuiMessage *message = NULL;
@@ -1249,6 +1297,8 @@ void ami_handle_msg(void)
 	        switch(result & WMHI_CLASSMASK) // class
    		   	{
 				case WMHI_MOUSEMOVE:
+					ami_gui_trap_mouse(gwin); /* re-assert mouse area */
+
 					drag_x_move = 0;
 					drag_y_move = 0;
 
@@ -3846,7 +3896,21 @@ bool gui_window_scroll_start(struct gui_window *g)
 bool gui_window_drag_start(struct gui_window *g, gui_drag_type type,
 		const struct rect *rect)
 {
-	DebugPrintF("drag start\n");
+	g->shared->drag_op = type;
+	if(rect) g->shared->ptr_lock = ami_ns_rect_to_ibox(g->shared, rect);
+
+	if(type == GDRAGGING_NONE)
+	{
+		SetWindowAttrs(gwin->win, WA_GrabFocus, 0,
+			WA_MouseLimits, NULL, TAG_DONE);
+
+		if(gwin->ptr_lock)
+		{
+			FreeVec(gwin->ptr_lock);
+			gwin->ptr_lock = NULL;
+		}
+	}
+
 	return true;
 }
 

amiga/gui.h

@@ -106,6 +106,8 @@ struct gui_window_2 {
 	struct AppIcon *appicon; /* iconify appicon */
 	struct DiskObject *dobj; /* iconify appicon */
 	struct Hook search_ico_hook;
+	gui_drag_type drag_op;
+	struct IBox *ptr_lock;
 };
 
 struct gui_window