Adding st embedder patch

README.md

@@ -15,6 +15,8 @@ Refer to [https://st.suckless.org/](https://st.suckless.org/) for details on the
 
 ### Changelog:
 
+2020-01-07 - Added st embedder patch
+
 2019-10-16 - Introduced [flexipatch-finalizer](https://github.com/bakkeby/flexipatch-finalizer)
 
 2019-09-17 - Added relativeborder, fix-keyboard-input, iso14755, visualbell, right-click-to-plumb, boxdraw and keyboard-select patches
@@ -81,6 +83,10 @@ Refer to [https://st.suckless.org/](https://st.suckless.org/) for details on the
    - [scrollback](https://st.suckless.org/patches/scrollback/)
       - allows you scroll back through terminal output using keyboard shortcuts or mousewheel
 
+   - st-embedder
+      - this patch allows clients to embed into the st window and can be useful if you tend to start X applications from the terminal
+      - the behavior is similar to Plan 9 where applications can take over windows
+
    - [spoiler](https://st.suckless.org/patches/spoiler/)
       - use inverted defaultbg/fg for selection when bg/fg are the same
 

patch/st_embedder_x.c

@@ -0,0 +1,50 @@
+static Window embed;
+
+void
+createnotify(XEvent *e)
+{
+	XWindowChanges wc;
+
+	if (embed || e->xcreatewindow.override_redirect)
+		return;
+
+	embed = e->xcreatewindow.window;
+
+	XReparentWindow(xw.dpy, embed, xw.win, 0, 0);
+	XSelectInput(xw.dpy, embed, PropertyChangeMask | StructureNotifyMask | EnterWindowMask);
+
+	XMapWindow(xw.dpy, embed);
+	sendxembed(XEMBED_EMBEDDED_NOTIFY, 0, xw.win, 0);
+
+	wc.width = win.w;
+	wc.height = win.h;
+	XConfigureWindow(xw.dpy, embed, CWWidth | CWHeight, &wc);
+
+	XSetInputFocus(xw.dpy, embed, RevertToParent, CurrentTime);
+}
+
+void
+destroynotify(XEvent *e)
+{
+	visibility(e);
+	if (embed == e->xdestroywindow.window) {
+		focus(e);
+	}
+}
+
+void
+sendxembed(long msg, long detail, long d1, long d2)
+{
+	XEvent e = { 0 };
+
+	e.xclient.window = embed;
+	e.xclient.type = ClientMessage;
+	e.xclient.message_type = xw.xembed;
+	e.xclient.format = 32;
+	e.xclient.data.l[0] = CurrentTime;
+	e.xclient.data.l[1] = msg;
+	e.xclient.data.l[2] = detail;
+	e.xclient.data.l[3] = d1;
+	e.xclient.data.l[4] = d2;
+	XSendEvent(xw.dpy, embed, False, NoEventMask, &e);
+}

patch/st_embedder_x.h

@@ -0,0 +1,7 @@
+#define XEMBED_EMBEDDED_NOTIFY 0
+#define XEMBED_WINDOW_ACTIVATE 1
+#define XEMBED_FOCUS_CURRENT   0
+
+static void createnotify(XEvent *e);
+static void destroynotify(XEvent *e);
+static void sendxembed(long msg, long detail, long d1, long d2);

patch/x_include.c

@@ -17,6 +17,9 @@
 #if RIGHTCLICKTOPLUMB_PATCH
 #include "rightclicktoplumb_x.c"
 #endif
+#if ST_EMBEDDER_PATCH
+#include "st_embedder_x.c"
+#endif
 #if VISUALBELL_2_PATCH || VISUALBELL_3_PATCH
 #include "visualbell.c"
 #endif

patch/x_include.h

@@ -14,6 +14,9 @@
 #if RIGHTCLICKTOPLUMB_PATCH
 #include "rightclicktoplumb_x.h"
 #endif
+#if ST_EMBEDDER_PATCH
+#include "st_embedder_x.h"
+#endif
 #if VISUALBELL_2_PATCH || VISUALBELL_3_PATCH
 #include "visualbell.h"
 #endif

patches.h

@@ -136,6 +136,16 @@
  */
 #define SCROLLBACK_MOUSE_ALTSCREEN_PATCH 0
 
+/* This patch allows clients to embed into the st window and is useful if you tend to
+ * start X applications from the terminal. For example:
+ *
+ *   $ surf -e $WINDOWID
+ *
+ * The behavior is similar to Plan 9 where applications can take over windows.
+ * URL TBC
+ */
+#define ST_EMBEDDER_PATCH 0
+
 /* Use inverted defaultbg/fg for selection when bg/fg are the same.
  * https://st.suckless.org/patches/spoiler/
  */

x.c

@@ -227,6 +227,10 @@ static void (*handler[LASTEvent])(XEvent *) = {
  */
 	[PropertyNotify] = propnotify,
 	[SelectionRequest] = selrequest,
+	#if ST_EMBEDDER_PATCH
+	[CreateNotify] = createnotify,
+	[DestroyNotify] = destroynotify,
+	#endif // ST_EMBEDDER_PATCH
 };
 
 /* Globals */
@@ -1189,7 +1193,11 @@ xinit(int cols, int rows)
 		| KeyReleaseMask
 		#endif // FIXIME_PATCH
 		| ExposureMask | VisibilityChangeMask | StructureNotifyMask
-		| ButtonMotionMask | ButtonPressMask | ButtonReleaseMask;
+		| ButtonMotionMask | ButtonPressMask | ButtonReleaseMask
+		#if ST_EMBEDDER_PATCH
+		| SubstructureNotifyMask | SubstructureRedirectMask
+		#endif // ST_EMBEDDER_PATCH
+		;
 	xw.attrs.colormap = xw.cmap;
 
 	#if !ALPHA_PATCH
@@ -1889,6 +1897,13 @@ visibility(XEvent *ev)
 void
 unmap(XEvent *ev)
 {
+	#if ST_EMBEDDER_PATCH
+	if (embed == ev->xunmap.window) {
+		embed = 0;
+		XRaiseWindow(xw.dpy, xw.win);
+		XSetInputFocus(xw.dpy, xw.win, RevertToParent, CurrentTime);
+	}
+	#endif // ST_EMBEDDER_PATCH
 	win.mode &= ~MODE_VISIBLE;
 }
 
@@ -1960,6 +1975,15 @@ focus(XEvent *ev)
 {
 	XFocusChangeEvent *e = &ev->xfocus;
 
+	#if ST_EMBEDDER_PATCH
+	if (embed && ev->type == FocusIn) {
+		XRaiseWindow(xw.dpy, embed);
+		XSetInputFocus(xw.dpy, embed, RevertToParent, CurrentTime);
+		sendxembed(XEMBED_FOCUS_IN, XEMBED_FOCUS_CURRENT, 0, 0);
+		sendxembed(XEMBED_WINDOW_ACTIVATE, 0, 0, 0);
+	}
+	#endif // ST_EMBEDDER_PATCH
+
 	if (e->mode == NotifyGrab)
 		return;
 
@@ -2108,9 +2132,21 @@ cmessage(XEvent *e)
 void
 resize(XEvent *e)
 {
+	#if ST_EMBEDDER_PATCH
+	XWindowChanges wc;
+	#endif // ST_EMBEDDER_PATCH
+
 	if (e->xconfigure.width == win.w && e->xconfigure.height == win.h)
 		return;
 
+	#if ST_EMBEDDER_PATCH
+	if (embed) {
+		wc.width = e->xconfigure.width;
+		wc.height = e->xconfigure.height;
+		XConfigureWindow(xw.dpy, embed, CWWidth | CWHeight, &wc);
+	}
+	#endif // ST_EMBEDDER_PATCH
+
 	cresize(e->xconfigure.width, e->xconfigure.height);
 }