create screenshot rectangle with X

1 files changed, 81 insertions, 6 deletions

diff --git a/xnap.c b/xnap.c
index 7a4f294..e95f137 100644
--- a/xnap.c
+++ b/xnap.c
@@ -1,37 +1,112 @@
 #include <stdlib.h>
 #include <stdio.h>
 
+#include <X11/X.h>
 #include <X11/Xlib.h>
+#include <X11/keysym.h>
+#include <X11/Xutil.h>
 
+#define MIN(x, y) (x < y ? x : y)
+#define MAX(x, y) (x > y ? x : y)
+
+struct pointer_t {
+	int    ret;
+	Bool   sel;
+	int    x0;
+	int    y0;
+	int    x1;
+	int    y1;
+};
+
+void compimg(void);
 void die(const char* s);
-void quit(void);
-void xsetup(void);
+void quit(Bool ex);
+void run(void);
+void setup(void);
 
 Display* dpy = NULL;
 Window root = None;
 int scr = -1;
+struct pointer_t p = {0};
+XImage* img = NULL;
 
 void die(const char* s)
 {
 	fprintf(stderr, "xnap: %s", s);
-	exit(1);
+	exit(EXIT_FAILURE);
 }
 
-void quit(void)
+void quit(Bool ex)
 {
+	XUngrabPointer(dpy, CurrentTime);
 	XCloseDisplay(dpy);
+	if (ex)
+		exit(EXIT_SUCCESS);
+}
+
+void run(void)
+{
+	XEvent ev;
+	for (;;) {
+		XNextEvent(dpy, &ev);
+
+		if (ev.type == KeyPress) {
+			KeySym ks = XLookupKeysym(&ev.xkey, 0);
+			if (ks == XK_Escape || ks == XK_q)
+				quit(True);
+		}
+
+		unsigned int b = ev.xbutton.button;
+		if (ev.type == ButtonPress && b == Button1) { /* start selecting */
+			p.sel = True;
+			p.x0 = p.x1 = ev.xbutton.x_root;
+			p.y0 = p.y1 = ev.xbutton.y_root;
+		}
+		else if (ev.type == MotionNotify && p.sel) { /* dragging selection */
+			p.x1 = ev.xmotion.x_root;
+			p.y1 = ev.xmotion.y_root;
+		}
+		else if (ev.type == ButtonRelease && p.sel && b == Button1) { /* release selection */
+			p.sel = False;
+
+			/* creating selection rectangle */
+			int recx = MIN(p.x0, p.x1);
+			int recy = MIN(p.y0, p.y1);
+			int recw = MAX(p.x0, p.x1) - recx;
+			int rech = MAX(p.y0, p.y1) - recy;
+
+			quit(False);
+			compimg()
+		}
+	}
 }
 
-void xsetup(void)
+void setup(void)
 {
+	/* X surface */
 	if (!(dpy = XOpenDisplay(NULL)))
 		die ("failed to open display");
 
 	int scr = DefaultScreen(dpy);
 	root = RootWindow(dpy, scr);
+
+	/* pointer */
+	p.ret = XGrabPointer(
+		dpy, root, False,
+		ButtonPressMask | ButtonReleaseMask | PointerMotionMask | KeyPressMask,
+		GrabModeAsync, GrabModeAsync, None, None, CurrentTime
+	);
+	if (p.ret != GrabSuccess)
+		die("XGrabPointer failed");
 }
 
-int main(void)
+int main(int argc, char** argv)
 {
+	(void) argc;
+	(void) argv;
+
+	setup();
+	quit(True); /* unreachable */
+
 	return EXIT_SUCCESS;
 }