Make the XForms frontend 'do the right thing' when exposing the work area

* if * libforms supports this.


git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@8737 a592a061-630c-0410-9148-cb99ea01b6c8

src/frontends/xforms/ChangeLog

@@ -1,3 +1,14 @@
+2004-05-04  Angus Leeming  <leeming@lyx.org>
+
+	This is a resurrection of John Levon's June 2002 code.
+
+	* xscreen.C (expose): do the 'right thing' and ouput an XEvent
+	request to expose the work area.
+
+	* XWorkArea.C (updateGeometry, paint): split the old redraw function
+	into two. Use the x, y data.
+	(work_area_handler): if an XEvent * is passed on FL_DRAW, then use it.
+
 2004-05-04  Angus Leeming  <leeming@lyx.org>
 
 	* XWorkArea.C (XWorkArea): revert the red color of the frame widget.

src/frontends/xforms/XWorkArea.C

@@ -175,8 +175,9 @@ XWorkArea::XWorkArea(LyXView & owner, int w, int h)
 	XGCValues val;
 
 	val.function = GXcopy;
+	val.graphics_exposures = false;
 	copy_gc = XCreateGC(fl_get_display(), RootWindow(fl_get_display(), 0),
-			    GCFunction, &val);
+			    GCFunction | GCGraphicsExposures, &val);
 }
 
 
@@ -188,17 +189,13 @@ XWorkArea::~XWorkArea()
 }
 
 
-void XWorkArea::redraw(int width, int height)
+void XWorkArea::updateGeometry(int width, int height)
 {
 	static int cur_width = -1;
 	static int cur_height = -1;
 
-	if (cur_width == width && cur_height == height && workareapixmap) {
-		XCopyArea(fl_get_display(),
-			  getPixmap(), getWin(), copy_gc,
-			  0, 0, width, height, xpos(), ypos());
+	if (cur_width == width && cur_height == height && workareapixmap)
 		return;
-	}
 
 	cur_width = width;
 	cur_height = height;
@@ -222,6 +219,20 @@ void XWorkArea::redraw(int width, int height)
 }
 
 
+void XWorkArea::paint(int x, int y, int w, int h)
+{
+	lyxerr[Debug::WORKAREA]
+		<< "XWorkarea::paint " << w << 'x' << h
+		<< '+' << x << '+' << y << endl;
+
+	updateGeometry(workWidth(), workHeight());
+	XCopyArea(fl_get_display(),
+		  getPixmap(), getWin(),
+		  copy_gc, x, y, w, h,
+		  work_area->x + x, work_area->y + y);
+}
+
+
 void XWorkArea::setScrollbarParams(int height, int pos, int line_height)
 {
 	// we need to cache this for scroll_cb
@@ -292,12 +303,35 @@ int XWorkArea::work_area_handler(FL_OBJECT * ob, int event,
 
 	switch (event) {
 
-	case FL_DRAW:
+	case FL_DRAW: {
 		if (!area->work_area || !area->work_area->form->visible)
 			return 1;
-		lyxerr[Debug::WORKAREA] << "Workarea event: DRAW" << endl;
-		area->redraw(area->workWidth(), area->workHeight());
+
+		if (ev) {
+			lyxerr[Debug::WORKAREA]
+				<< "work_area_handler, handling X11 "
+				"expose event "
+				<< ev->xexpose.width << 'x'
+				<< ev->xexpose.height << '+'
+				<< ev->xexpose.x << '+'
+				<< ev->xexpose.y << endl;
+
+			// X11 generates XEvents with x, y relative to the
+			// top left corner of the window.
+			// XScreen::expose emulates this behaviour.
+			// We therefore need to remove this offset before
+			// generating the pixmap.
+			 int const x = ev->xexpose.x - ob->x;
+			 int const y = ev->xexpose.y - ob->y;
+
+			area->paint(x, y,
+				    ev->xexpose.width, ev->xexpose.height);
+		} else
+			area->paint(0, 0,
+				    area->workWidth(), area->workHeight());
+
 		break;
+	}
 
 	case FL_PUSH:
 		if (!ev || ev->xbutton.button == 0) break;

src/frontends/xforms/XWorkArea.h

@@ -65,7 +65,10 @@ public:
 private:
 	/// generate the pixmap, and copy backing pixmap to it,
 	/// and send resize event if needed
-	void redraw(int, int);
+	void updateGeometry(int, int);
+
+	///
+	void paint(int x, int y, int w, int h);
 
 	/// GC used for copying to the screen
 	GC copy_gc;

src/frontends/xforms/xscreen.C

@@ -79,7 +79,7 @@ void XScreen::setCursorColor()
 
 void XScreen::showCursor(int x, int y, int h, Cursor_Shape shape)
 {
-	// Update the cursor color. (a little slow dooing it like this ??)
+	// Update the cursor color. (a little slow doing it like this ??)
 	setCursorColor();
 
 	cursor_x_ = x;
@@ -153,13 +153,21 @@ void XScreen::removeCursor()
 
 void XScreen::expose(int x, int y, int w, int h)
 {
-	lyxerr[Debug::GUI] << "expose " << w << 'x' << h
+	lyxerr[Debug::GUI] << "XScreen::expose " << w << 'x' << h
 		<< '+' << x << '+' << y << endl;
-	XCopyArea(fl_get_display(),
-		  owner_.getPixmap(),
-		  owner_.getWin(),
-		  gc_copy,
-		  x, y, w, h,
-		  x + owner_.xpos(),
-		  y + owner_.ypos());
+
+	XEvent ev;
+
+	ev.type = Expose;
+	ev.xexpose.window = owner_.getWin();
+	// Adjust the x,y data so that XWorkArea can handle XEvents
+	// received from here in identical fashion to those it receives
+	// direct from X11.
+	ev.xexpose.x = owner_.xpos() + x;
+	ev.xexpose.y = owner_.ypos() + y;
+	ev.xexpose.width = w;
+	ev.xexpose.height = h;
+	ev.xexpose.count = 0;
+
+	XSendEvent(fl_get_display(), owner_.getWin(), False, 0, &ev);
 }