xruler

commit 03bb532f65248cda454c924618de941f6509857d
Author: Matthias Balk <mbalk@mbalk.de>
Date:   Mon, 30 Sep 2019 19:45:27 +0200

initial commit

Diffstat:
A
Makefile
 | 
5
+++++
A
xruler.c
 | 
109
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

2 files changed, 114 insertions(+), 0 deletions(-)
diff --git a/Makefile b/Makefile
@@ -0,0 +1,5 @@
+CC = gcc
+LINKER_FLAGS = `pkg-config --libs xcb`
+
+xruler: xruler.c
+	gcc xruler.c $(LINKER_FLAGS) -o xruler
diff --git a/xruler.c b/xruler.c
@@ -0,0 +1,109 @@
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <xcb/xcb.h>
+
+
+static uint32_t width = 1500;
+static uint32_t height = 50;
+
+int main (int argc, char** argv)
+{
+  /* Open the connection to the X server */
+  xcb_connection_t* connection = xcb_connect(NULL, NULL);
+
+
+  /* Get the first screen */
+  xcb_screen_t* screen =
+      xcb_setup_roots_iterator(xcb_get_setup (connection)).data;
+
+
+  /* Create black (foreground) graphic context */
+  xcb_drawable_t  window     = screen->root;
+  xcb_gcontext_t  foreground = xcb_generate_id (connection);
+  uint32_t        mask       = XCB_GC_FOREGROUND | XCB_GC_GRAPHICS_EXPOSURES;
+  uint32_t        values[2]  = {screen->black_pixel, 0};
+
+  xcb_create_gc(connection, foreground, window, mask, values);
+
+
+  /* Create a window */
+  window = xcb_generate_id(connection);
+
+  mask = XCB_CW_BACK_PIXEL | XCB_CW_EVENT_MASK;
+  values[0] = screen->white_pixel;
+  values[1] = XCB_EVENT_MASK_EXPOSURE |
+              XCB_EVENT_MASK_KEY_PRESS |
+              XCB_EVENT_MASK_POINTER_MOTION;
+
+  xcb_create_window(connection,                    /* connection    */
+                    XCB_COPY_FROM_PARENT,          /* depth         */
+                    window,                        /* window Id     */
+                    screen->root,                  /* parent window */
+                    0, 0,                          /* x, y          */
+                    width, height,                 /* width, height */
+                    0,                             /* border_width  */
+                    XCB_WINDOW_CLASS_INPUT_OUTPUT, /* class         */
+                    screen->root_visual,           /* visual        */
+                    mask, values);                 /* masks         */
+
+
+  /* Map the window on the screen and flush*/
+  xcb_map_window (connection, window);
+  xcb_flush (connection);
+
+
+  /* draw primitives */
+  xcb_generic_event_t* event;
+  while (event = xcb_wait_for_event(connection)) {
+    switch (event->response_type & ~0x80) {
+      case XCB_EXPOSE:
+      {
+          for (int i = 1; i < 1000; i++)
+          {
+            int y = 15;
+            if (i % 50 == 0) y = 45;
+            else if (i % 10 == 0) y = 35;
+            else if (i % 5 == 0) y = 25;
+
+            xcb_point_t  polyline[] = { {5*i, 0}, {0, y} };
+            xcb_poly_line (
+                connection, XCB_COORD_MODE_PREVIOUS, window, foreground,
+                2, polyline);
+          }
+
+          /* flush the request */
+          xcb_flush (connection);
+
+          break;
+      }
+
+      case XCB_KEY_PRESS:
+      {
+        xcb_key_press_event_t* kp = (xcb_key_press_event_t*) event;
+
+        if (kp->detail == 24)                         /* q */
+        {
+          free(event);
+          xcb_disconnect(connection);
+          return 0;
+        }
+      }
+
+      case XCB_MOTION_NOTIFY:
+      {
+        xcb_motion_notify_event_t* motion = (xcb_motion_notify_event_t*) event;
+        printf("Mouse moved in window %u, at coordinates (%u,%u)\n",
+                motion->event, motion->event_x, motion->event_y );
+        break;
+      }
+
+      default:
+        /* Unknown event type, ignore it */
+        break;
+    }
+
+    free (event);
+  }
+}