Initial revision

1 files changed, 171 insertions, 0 deletions

diff --git a/unix/tkUnixDraw.c b/unix/tkUnixDraw.c
new file mode 100644
index 0000000..65bf2e4
--- /dev/null
+++ b/unix/tkUnixDraw.c
@@ -0,0 +1,171 @@
+/* 
+ * tkUnixDraw.c --
+ *
+ *	This file contains X specific drawing routines.
+ *
+ * Copyright (c) 1995 Sun Microsystems, Inc.
+ *
+ * See the file "license.terms" for information on usage and redistribution
+ * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
+ *
+ * SCCS: @(#) tkUnixDraw.c 1.9 97/03/21 11:16:18
+ */
+
+#include "tkPort.h"
+#include "tkInt.h"
+
+/*
+ * The following structure is used to pass information to
+ * ScrollRestrictProc from TkScrollWindow.
+ */
+
+typedef struct ScrollInfo {
+    int done;			/* Flag is 0 until filtering is done. */
+    Display *display;		/* Display to filter. */
+    Window window;		/* Window to filter. */
+    TkRegion region;		/* Region into which damage is accumulated. */
+    int dx, dy;			/* Amount by which window was shifted. */
+} ScrollInfo;
+
+/*
+ * Forward declarations for procedures declared later in this file:
+ */
+
+static Tk_RestrictAction	ScrollRestrictProc _ANSI_ARGS_((
+    				    ClientData arg, XEvent *eventPtr));
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TkScrollWindow --
+ *
+ *	Scroll a rectangle of the specified window and accumulate
+ *	damage information in the specified Region.
+ *
+ * Results:
+ *	Returns 0 if no damage additional damage was generated.  Sets
+ *	damageRgn to contain the damaged areas and returns 1 if
+ *	GraphicsExpose events were detected.
+ *
+ * Side effects:
+ *	Scrolls the bits in the window and enters the event loop
+ *	looking for damage events.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TkScrollWindow(tkwin, gc, x, y, width, height, dx, dy, damageRgn)
+    Tk_Window tkwin;		/* The window to be scrolled. */
+    GC gc;			/* GC for window to be scrolled. */
+    int x, y, width, height;	/* Position rectangle to be scrolled. */
+    int dx, dy;			/* Distance rectangle should be moved. */
+    TkRegion damageRgn;		/* Region to accumulate damage in. */
+{
+    Tk_RestrictProc *oldProc;
+    ClientData oldArg, dummy;
+    ScrollInfo info;
+    
+    XCopyArea(Tk_Display(tkwin), Tk_WindowId(tkwin), Tk_WindowId(tkwin), gc,
+	    x, y, (unsigned int) width, (unsigned int) height, x + dx, y + dy);
+
+    info.done = 0;
+    info.window = Tk_WindowId(tkwin);
+    info.display = Tk_Display(tkwin);
+    info.region = damageRgn;
+    info.dx = dx;
+    info.dy = dy;
+
+    /*
+     * Sync the event stream so all of the expose events will be on the
+     * Tk event queue before we start filtering.  This avoids busy waiting
+     * while we filter events.
+     */
+
+    TkpSync(info.display);
+    oldProc = Tk_RestrictEvents(ScrollRestrictProc, (ClientData) &info,
+	    &oldArg);
+    while (!info.done) {
+	Tcl_ServiceEvent(TCL_WINDOW_EVENTS);
+    }
+    Tk_RestrictEvents(oldProc, oldArg, &dummy);
+
+    return XEmptyRegion((Region) damageRgn) ? 0 : 1;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * ScrollRestrictProc --
+ *
+ *	A Tk_RestrictProc used by TkScrollWindow to gather up Expose
+ *	information into a single damage region.  It accumulates damage
+ *	events on the specified window until a NoExpose or the last
+ *	GraphicsExpose event is detected.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Discards Expose events after accumulating damage information
+ *	for a particular window.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static Tk_RestrictAction
+ScrollRestrictProc(arg, eventPtr)
+    ClientData arg;
+    XEvent *eventPtr;
+{
+    ScrollInfo *info = (ScrollInfo *) arg;
+    XRectangle rect;
+
+    /*
+     * Defer events which aren't for the specified window.
+     */
+
+    if (info->done || (eventPtr->xany.display != info->display)
+	    || (eventPtr->xany.window != info->window)) {
+	return TK_DEFER_EVENT;
+    }
+
+    if (eventPtr->type == NoExpose) {
+	info->done = 1;
+    } else if (eventPtr->type == GraphicsExpose) {
+	rect.x = eventPtr->xgraphicsexpose.x;
+	rect.y = eventPtr->xgraphicsexpose.y;
+	rect.width = eventPtr->xgraphicsexpose.width;
+	rect.height = eventPtr->xgraphicsexpose.height;
+	XUnionRectWithRegion(&rect, (Region) info->region,
+		(Region) info->region);
+
+	if (eventPtr->xgraphicsexpose.count == 0) {
+	    info->done = 1;
+	}
+    } else if (eventPtr->type == Expose) {
+
+	/*
+	 * This case is tricky.  This event was already queued before
+	 * the XCopyArea was issued.  If this area overlaps the area
+	 * being copied, then some of the copied area may be invalid.
+	 * The easiest way to handle this case is to mark both the
+	 * original area and the shifted area as damaged.
+	 */
+
+	rect.x = eventPtr->xexpose.x;
+	rect.y = eventPtr->xexpose.y;
+	rect.width = eventPtr->xexpose.width;
+	rect.height = eventPtr->xexpose.height;
+	XUnionRectWithRegion(&rect, (Region) info->region,
+		(Region) info->region);
+	rect.x += info->dx;
+	rect.y += info->dy;
+	XUnionRectWithRegion(&rect, (Region) info->region,
+		(Region) info->region);
+    } else {
+	return TK_DEFER_EVENT;
+    }
+    return TK_DISCARD_EVENT;
+}
+