static xcb_gc_t getFontGC(xcb_connection_t *connection,
xcb_screen_t *screen,
xcb_window_t window,
const char *fontName) {
xcb_font_t font = xcb_generate_id(connection);
xcb_void_cookie_t fontCookie = xcb_open_font_checked(connection,
font,
strlen(fontName),
fontName);
testCookie(fontCookie, connection, "can't open font");
xcb_gcontext_t gc = xcb_generate_id(connection);
uint32_t mask = XCB_GC_FOREGROUND | XCB_GC_BACKGROUND | XCB_GC_FONT;
uint32_t value_list[3];
value_list[0] = screen->black_pixel;
value_list[1] = screen->white_pixel;
value_list[2] = font;
xcb_void_cookie_t gcCookie = xcb_create_gc_checked(connection,
gc,
window,
mask,
value_list);
testCookie(gcCookie, connection, "can't create gc");
fontCookie = xcb_close_font_checked(connection, font);
testCookie(fontCookie, connection, "can't close font");
return gc;
}
void drawButton (xcb_connection_t *connection,
xcb_screen_t *screen,
xcb_window_t window,
int16_t x1,
int16_t y1,
const char *label )
{
uint8_t length = strlen (label);
int16_t inset = 2;
int16_t width = 7 * length + 2 * (inset + 1);
int16_t height = 13 + 2 * (inset + 1);
xcb_point_t points[5];
points[0].x = x1;
points[0].y = y1;
points[1].x = x1 + width;
points[1].y = y1;
points[2].x = x1 + width;
points[2].y = y1 - height;
points[3].x = x1;
points[3].y = y1 - height;
points[4].x = x1;
points[4].y = y1;
xcb_colormap_t colors[2];
colors[0]=screen->black_pixel;
colors[1]=screen->white_pixel;
xcb_gcontext_t gc = getFontGC2 (connection, screen, window,colors, "7x13");
uint32_t gcv[1]= {screen->black_pixel};
xcb_change_gc(connection,gc, XCB_GC_FOREGROUND, gcv);
xcb_void_cookie_t lineCookie = xcb_poly_line_checked (connection,
XCB_COORD_MODE_ORIGIN,
window,
gc,
5,
points );
testCookie (lineCookie, connection, "can't draw lines");
xcb_void_cookie_t textCookie = xcb_image_text_8_checked (connection,
length,
window,
gc,
x1 + inset + 1,
y1 - inset - 1,
label );
testCookie (textCookie, connection, "can't paste text");
xcb_void_cookie_t gcCookie = xcb_free_gc (connection, gc);
testCookie (gcCookie, connection, "can't free gc");
};
static void drawButton(xcb_connection_t *connection,
xcb_screen_t *screen,
xcb_window_t window,
int16_t x1,
int16_t y1,
const char *label) {
uint8_t length = strlen(label);
int16_t inset = 2;
int16_t width = 7 * length + 2 * (inset + 1);
int16_t height =13 + 2 * (inset + 1);
xcb_point_t points[5];
points[0].x = x1;
points[0].y = y1;
points[1].x = x1 + width;
points[1].y = y1;
points[2].x = x1 + width;
points[2].y = y1 - height;
points[3].x = x1;
points[3].y = y1 - height;
points[4].x = x1;
points[4].y = y1;
xcb_gcontext_t gc = getFontGC(connection, screen, window, "fixed");
xcb_void_cookie_t lineCookie = xcb_poly_line_checked(connection,
XCB_COORD_MODE_ORIGIN,
window,
gc,
5,
points);
testCookie(lineCookie, connection, "can't draw lines");
xcb_void_cookie_t textCookie = xcb_image_text_8_checked(connection,
length,
window,
gc,
x1 + inset +1,
y1 - inset -1,
label);
testCookie(textCookie, connection, "can't paste text");
xcb_void_cookie_t gcCookie = xcb_free_gc(connection, gc);
testCookie(gcCookie, connection, "can't free gc");
}
static void setCursor(xcb_connection_t *connection,
xcb_screen_t *screen,
xcb_window_t window,
int cursorId) {
xcb_font_t font = xcb_generate_id(connection);
xcb_void_cookie_t fontCookie = xcb_open_font_checked(connection,
font,
strlen("cursor"),
"cursor");
testCookie(fontCookie, connection, "can't open font");
xcb_cursor_t cursor = xcb_generate_id(connection);
xcb_create_glyph_cursor(connection,
cursor,
font,
font,
cursorId,
cursorId + 1,
0,0,0,0,0,0);
xcb_gcontext_t gc = xcb_generate_id(connection);
uint32_t mask = XCB_GC_FOREGROUND | XCB_GC_BACKGROUND | XCB_GC_FONT;
uint32_t values_list[3];
values_list[0] = screen->black_pixel;
values_list[1] = screen->white_pixel;
values_list[2] = font;
xcb_void_cookie_t gcCookie = xcb_create_gc_checked(connection, gc, window, mask, values_list);
testCookie(gcCookie, connection, "can't create gc");
mask = XCB_CW_CURSOR;
uint32_t value_list = cursor;
xcb_change_window_attributes(connection, window, mask, &value_list);
xcb_free_cursor(connection, cursor);
fontCookie = xcb_close_font_checked(connection, font);
testCookie(fontCookie, connection, "can't close font");
}
static void drawText(xcb_connection_t *connection,
xcb_screen_t *screen,
xcb_window_t window,
int16_t x1,
int16_t y1,
const char *label) {
xcb_gcontext_t gc = getFontGC(connection, screen, window, "fixed");
xcb_void_cookie_t textCookie = xcb_image_text_8_checked(connection,
strlen (label),
window,
gc,
x1,
y1,
label);
testCookie(textCookie, connection, "can't paste text");
xcb_void_cookie_t gcCookie = xcb_free_gc(connection, gc);
testCookie(gcCookie, connection, "can't free gc");
}
int main() {
//get the connection
int screenNum;
xcb_connection_t *connection = xcb_connect(NULL, &screenNum);
if (!connection) {
fprintf(stderr, "ERROR: can't connect to an X server\n");
return -1;
}
// get the current screen
xcb_screen_iterator_t iter = xcb_setup_roots_iterator(xcb_get_setup(connection));
// we want the screen at index screenNum of the iterator
for (int i = 0; i < screenNum; i++) {
xcb_screen_next(&iter);
}
xcb_screen_t *screen = iter.data;
if(!screen){
fprintf(stderr, "ERROR: can't get the current screen\n");
xcb_disconnect(connection);
return -1;
}
// create the window
xcb_window_t window = xcb_generate_id(connection);
uint32_t mask = XCB_CW_BACK_PIXEL |XCB_CW_EVENT_MASK;
uint32_t values[2];
values[0] = screen->white_pixel;
values[1] = XCB_EVENT_MASK_KEY_RELEASE |
XCB_EVENT_MASK_BUTTON_PRESS |
XCB_EVENT_MASK_EXPOSURE |
XCB_EVENT_MASK_POINTER_MOTION;
xcb_void_cookie_t windowCookie = xcb_create_window_checked(connection,
screen->root_depth,
window,
screen->root,
20,200,WIDTH,HEIGHT,
0,
XCB_WINDOW_CLASS_INPUT_OUTPUT,
screen->root_visual,
mask, values);
testCookie(windowCookie, connection, "can't create window");
xcb_void_cookie_t mapCookie = xcb_map_window_checked(connection, window);
testCookie(mapCookie, connection, "can't map window");
setCursor(connection, screen, window, 68);
xcb_flush(connection);
// Event loop
uint8_t isHand = 0;
while (1) {
xcb_generic_event_t *event = xcb_poll_for_event(connection);
if(event){
switch (event->response_type & ~0x80) {
case XCB_EXPOSE: {
char *text = "click here to change cursor";
drawButton(connection,
screen,
window,
(WIDTH - 7 * strlen(text)) / 2,
(WIDTH -16) / 2,
text);
text = "Press ESC key to exit...";
drawText(connection,
screen,
window,
10,
HEIGHT -10,
text);
break;
}
case XCB_BUTTON_PRESS: {
xcb_button_press_event_t *press = (xcb_button_press_event_t *)event;
int length = strlen("click here to change cursor");
if ((press->event_x >= (WIDTH -7 * length) / 2) &&
(press->event_x <= ((WIDTH -7 * length) /2 + 7 * length + 6)) &&
(press->event_y >= (HEIGHT -16) / 2 - 19) &&
(press->event_y <= ((HEIGHT -16) / 2))) {
isHand = 1 - isHand;
}
if (isHand){
setCursor(connection, screen, window, 58);
}
else{
setCursor(connection, screen, window, 68);
}
}
case XCB_KEY_RELEASE: {
xcb_key_release_event_t *kr = (xcb_key_release_event_t *)event;
switch (kr->detail) {
// ESC
case 9:
free(event);
xcb_disconnect(connection);
return 0;
}
}
}
free(event);
}
}
return 0;
}
