overlay: Add a X11 window backend

Useful for remote hosts.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 186 insertions, 0 deletions

diff --git a/overlay/x11/x11-window.c b/overlay/x11/x11-window.c
new file mode 100644
index 00000000..0bce9a1a
--- /dev/null
+++ b/overlay/x11/x11-window.c
@@ -0,0 +1,186 @@
+#include <X11/Xlib.h>
+#include <cairo.h>
+#include <cairo-xlib.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "../overlay.h"
+
+struct x11_window {
+	struct overlay base;
+	Display *dpy;
+	Window win;
+	int width, height;
+	int visible;
+};
+
+static inline struct x11_window *to_x11_window(struct overlay *o)
+{
+	return (struct x11_window *)o;
+}
+
+static int noop(Display *dpy, XErrorEvent *event)
+{
+	return 0;
+}
+
+static void x11_window_show(struct overlay *overlay)
+{
+	struct x11_window *priv = to_x11_window(overlay);
+
+	if (!priv->visible) {
+		XMapWindow(priv->dpy, priv->win);
+		priv->visible = true;
+	}
+
+	XFlush(priv->dpy);
+}
+
+static void x11_window_position(struct overlay *overlay,
+				enum position p)
+{
+	struct x11_window *priv = to_x11_window(overlay);
+	Screen *scr = ScreenOfDisplay(priv->dpy, DefaultScreen(priv->dpy));
+	int x, y;
+
+	switch (p & 7) {
+	default:
+	case 0: x = 0; break;
+	case 1: x = (scr->width - priv->width)/2; break;
+	case 2: x = scr->width - priv->width; break;
+	}
+
+	switch ((p >> 4) & 7) {
+	default:
+	case 0: y = 0; break;
+	case 1: y = (scr->height - priv->height)/2; break;
+	case 2: y = scr->height - priv->height; break;
+	}
+
+	if (priv->visible) {
+		XMoveWindow(priv->dpy, priv->win, x, y);
+		XFlush(priv->dpy);
+	}
+}
+
+static void x11_window_hide(struct overlay *overlay)
+{
+	struct x11_window *priv = to_x11_window(overlay);
+	if (priv->visible) {
+		XUnmapWindow(priv->dpy, priv->win);
+		XFlush(priv->dpy);
+		priv->visible = false;
+	}
+}
+
+static void x11_window_destroy(void *data)
+{
+	struct x11_window *priv = data;
+	XDestroyWindow(priv->dpy, priv->win);
+	XCloseDisplay(priv->dpy);
+	free(priv);
+}
+
+cairo_surface_t *
+x11_window_create(enum position position, int *width, int *height)
+{
+	Display *dpy;
+	Screen *scr;
+	Window win;
+	int screen;
+	cairo_surface_t *surface;
+	XSetWindowAttributes attr;
+	struct x11_window *priv;
+	int x, y, w, h;
+
+	dpy = XOpenDisplay(NULL);
+	if (dpy == NULL)
+		return NULL;
+
+	screen = DefaultScreen(dpy);
+	scr = XScreenOfDisplay(dpy, screen);
+
+	XSetErrorHandler(noop);
+
+	if (*width == -1) {
+		w = scr->width;
+		switch (position & 7) {
+		default:
+		case 0:
+		case 2: w >>= 1; break;
+		}
+	} else if (*width > scr->width) {
+		w = scr->width;
+	} else
+		w = *width;
+
+	if (*height == -1) {
+		h = scr->height;
+		switch ((position >> 4) & 7) {
+		default:
+		case 0:
+		case 2: h >>= 1; break;
+		}
+	} else if (*height > scr->height)
+		h = scr->height;
+	else
+		h = *height;
+
+	switch (position & 7) {
+	default:
+	case 0: x = 0; break;
+	case 1: x = (scr->width - w)/2; break;
+	case 2: x = scr->width - w; break;
+	}
+
+	switch ((position >> 4) & 7) {
+	default:
+	case 0: y = 0; break;
+	case 1: y = (scr->height - h)/2; break;
+	case 2: y = scr->height - h; break;
+	}
+
+	attr.override_redirect = True;
+	win = XCreateWindow(dpy, DefaultRootWindow(dpy),
+			   x, y, w, h, 0,
+			   DefaultDepth(dpy, screen),
+			   InputOutput,
+			   DefaultVisual(dpy, screen),
+			   CWOverrideRedirect, &attr);
+
+	surface = cairo_xlib_surface_create(dpy, win, DefaultVisual (dpy, screen), w, h);
+	if (cairo_surface_status(surface))
+		goto err_win;
+
+	priv = malloc(sizeof(*priv));
+	if (priv == NULL)
+		goto err_surface;
+
+	priv->base.surface = surface;
+	priv->base.show = x11_window_show;
+	priv->base.position = x11_window_position;
+	priv->base.hide = x11_window_hide;
+
+	priv->dpy = dpy;
+	priv->win = win;
+	priv->visible = false;
+
+	priv->width = w;
+	priv->height = h;
+
+	cairo_surface_set_user_data(surface, &overlay_key, priv, x11_window_destroy);
+
+	*width = w;
+	*height = h;
+	return surface;
+
+err_surface:
+	cairo_surface_destroy(surface);
+err_win:
+	XDestroyWindow(dpy, win);
+	XCloseDisplay(dpy);
+	return NULL;
+}