I've looked through some of the docs but can't find a nice description of how to get the cursor's position (in terms of pixels from top-left 0,0) in the window on click.
Any help is appreciated :D
Here's a minimal program that reports where the mouse is clicked. It just picks up the Button Press event which contains the x,y (top-left is 0,0) position of the mouse pointer in the window.
#include <stdio.h>
#include <X11/Xlib.h>
int main(int argc, char**argv)
{
Display *display = XOpenDisplay(NULL);
Window window = XCreateSimpleWindow(
display, RootWindow(display,0), 0, 0,
600, 600, 1, BlackPixel(display, 0),
WhitePixel(display, 0));
XMapWindow(display, window);
XSelectInput(display, window, ButtonPressMask);
XEvent event;
while (1)
{
XNextEvent(display, &event);
switch (event.type) {
case ButtonPress:
printf("Clicked at %d,%d\n", event.xbutton.x, event.xbutton.y);
break;
}
}
return 0;
}
Related
I can only get events after the window has moved, not while it is moving.
I want to get moving events in real time. Please,what should I do?
#include <X11/X.h>
#include <X11/Xlib.h>
#include <stdio.h>
int main(int argv, char **agrc)
{
Display *dpy = XOpenDisplay(NULL);
Window w = XCreateSimpleWindow(dpy, RootWindow(dpy, DefaultScreen(dpy)), 10, 10, 800, 400, 1, BlackPixel(dpy, DefaultScreen(dpy)), WhitePixel(dpy, DefaultScreen(dpy)));
XSelectInput(dpy, w, StructureNotifyMask);
XMapWindow(dpy, w);
XEvent event;
for (;;)
{
XNextEvent(dpy, &event);
if(event.type == ConfigureNotify)
{
XConfigureEvent x = event.xconfigure;
printf("config[%d]{%d,%d,%d,%d}\n", x.window, x.x, x.y, x.width, x.height);
}
}
XDestroyWindow(dpy, w);
XCloseDisplay(dpy);
return 0;
}
I'm not sure how to use a software SDL_Renderer to render to a window while resizing that window. For example, I expect the following code to constantly display a fully black window even as the uses resizes the window. Instead, when the user resizes the window, it's not filled with black, you get kind of "streaks" of black against a transparent background.
I'm sure I could cobble something together with catching resize events, maybe using SDL_RenderFilleRect() instead of SDL_RenderClear(), but fundamentally I just don't know what I should be doing at all. Should I be freeing the SDL_Surface and getting an entirely new surface and renderer every time the window resizes? Should I be calling SDL_RenderSetViewport()?
#include <SDL.h>
int main()
{
SDL_Init(SDL_INIT_EVERYTHING);
SDL_Window *window = SDL_CreateWindow(
"Main Window",
SDL_WINDOWPOS_UNDEFINED,
SDL_WINDOWPOS_UNDEFINED,
600,
600,
SDL_WINDOW_SHOWN | SDL_WINDOW_RESIZABLE
);
SDL_Surface *window_surface = SDL_GetWindowSurface(window);
SDL_Renderer *renderer = SDL_CreateSoftwareRenderer(window_surface);
SDL_Event event;
bool quit = false;
while (!quit)
{
while (SDL_PollEvent(&event))
{
switch (event.type)
{
case SDL_QUIT:
quit = true;
break;
}
}
SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
SDL_RenderClear(renderer);
SDL_RenderPresent(renderer);
SDL_UpdateWindowSurface(window);
SDL_Delay(1000 / 60);
}
SDL_Quit();
return 0;
}
I would like to open a "dock type" window without its title bar with x11 in C and I want to capture a key press (Ctrl-q) to close it. The actual code does not capture the key presses to the active window as they are all sent and printed in the terminal. Almost all the Ctrl key presses are somehow not detected. The only key presses that actually work on the opened window are Ctrl-c. I am aware of the _MOTIF_WM_HINTS property but it has the disadvantage to display a window icon in the panel to show a new opened window.
How can I have a "dock type" window while not losing the ability to detect key presses to the active window?
Here is the code basically copied from two other posts here and here
#include <stdio.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/Xatom.h>
#include <X11/keysym.h>
int main(int argc, char **argv)
{
Display *dpy = XOpenDisplay(0);
int blackColor = BlackPixel(dpy, DefaultScreen(dpy));
int whiteColor = WhitePixel(dpy, DefaultScreen(dpy));
Window w = XCreateSimpleWindow(dpy, DefaultRootWindow(dpy), 0, 0,
200, 100, 0, blackColor, blackColor);
//Tell X Server to send MapNotify events
XSelectInput(dpy, w, StructureNotifyMask | KeyPressMask);
Atom window_type = XInternAtom(dpy, "_NET_WM_WINDOW_TYPE", False);
long value = XInternAtom(dpy, "_NET_WM_WINDOW_TYPE_DOCK", False);
XChangeProperty(dpy, w, window_type, 4, 32,
PropModeReplace,
(unsigned char *)&value, 1);
//Make window appear
XMapWindow(dpy, w);
//Graphics Context
GC gc = XCreateGC(dpy, w, 0, 0);
//Set white color for drawing
XSetForeground(dpy, gc, whiteColor);
//Wait for the MapNotify event
for(;;) {
XEvent e;
XNextEvent(dpy, &e);
if (e.type == MapNotify) {
break;
}
}
//Draw the line
XDrawLine(dpy, w, gc, 10, 60, 180, 20);
//Send the "DrawLine" request to the server
XFlush(dpy);
char text[255];
XEvent e;
KeySym key;
int numKeys = 0;
for(;;) {
XNextEvent(dpy, &e);
if(e.type == KeyPress) {
if((numKeys = XLookupString(&e.xkey, text, 255, &key, 0))) {
if(e.xkey.state == ControlMask && key == XK_q) {
printf("CTRL-Q\n");
break;
}
}
}
}
if (dpy && gc) XFreeGC(dpy, gc);
if (dpy && w) XDestroyWindow(dpy, w);
if (dpy) XCloseDisplay(dpy);
return 0;
}
Compiled with:
gcc main.c -L/usr/X11R6/lib -lX11 -lm && ./a.out
I've also looked at the _NET_WM_STRUT_PARTIAL property but I haven't been succesful at implementing it.
I am designing an app that having the ID of an X11 window to draw a rectangle.
The problem I have is that I can not draw nothing in the window.
Code
One obvious error is that you did not select ExposureMask in call to XSelectInput, so you will not receive Expose event you are waiting for.
Other possible problem is not setting foreground drawing color of the GC by XSetForegroundColor, default is black. And using default gc of screen may fail if the window has different color depth or different visual. Other important GC attributes issubwindow_mode (whether to draw over child windows).
Still, after I did those changes, the program only works for me (draws a rectangle) on root window and xev, but not for xterm, no expose events.
This is my fixed version:
#include <X11/Xlib.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
int main (int argc, char *argv[]){
Window win;
Display *display;
XEvent e;
display = XOpenDisplay(NULL);
if(display==NULL){
fprintf(stderr,"Cannot open Display\n");
exit(1);
}
int s = DefaultScreen(display);
//unsigned long *id = (unsigned long*)(argv[1]);
sscanf(argv[1], "0x%x", &win);
if(!XSelectInput(display,win,StructureNotifyMask | ExposureMask)){
fprintf(stderr,"Cannot select Display\n");
return -1;
}
if(!XMapWindow(display,win)){
fprintf(stderr,"Cannot map Display\n");
return -1;
}
XGCValues gcv;
gcv.subwindow_mode = IncludeInferiors;
GC gc = XCreateGC(display, win, GCSubwindowMode,
&gcv);
XSetForeground(display, gc, 0xff00ff00);
XSetPlaneMask(display, gc, 0xffffffff);
while (1) {
puts("waiting for event\n");
XNextEvent(display, &e);
puts("got event\n");
if (e.type == Expose) {
printf("drawing\n");
XFillRectangle(display, win, gc, 20, 20, 100, 100);
}
if (e.type == KeyPress)
break;
}
return 0;
}
Is there a way to create a window with Xlib which only display the border lines, title, close button and that you can move with the mouse? The content of the window must be empty (or "totally transparent", although "transparency" sounds more like an effect I don't need). Basically the window should show the background area.
I'm not sure if it is what you want, but following code creates an X window with transparent background but still using the window decoration of your window manager.
It will only work though if your X11 and graphics hardware configuration supports visuals with a depth of 32 bit.
#include <X11/Xlib.h>
#include <X11/Xutil.h>
int main(int argc, char* argv[])
{
Display* display = XOpenDisplay(NULL);
XVisualInfo vinfo;
XMatchVisualInfo(display, DefaultScreen(display), 32, TrueColor, &vinfo);
XSetWindowAttributes attr;
attr.colormap = XCreateColormap(display, DefaultRootWindow(display), vinfo.visual, AllocNone);
attr.border_pixel = 0;
attr.background_pixel = 0;
Window win = XCreateWindow(display, DefaultRootWindow(display), 0, 0, 300, 200, 0, vinfo.depth, InputOutput, vinfo.visual, CWColormap | CWBorderPixel | CWBackPixel, &attr);
XSelectInput(display, win, StructureNotifyMask);
GC gc = XCreateGC(display, win, 0, 0);
Atom wm_delete_window = XInternAtom(display, "WM_DELETE_WINDOW", 0);
XSetWMProtocols(display, win, &wm_delete_window, 1);
XMapWindow(display, win);
int keep_running = 1;
XEvent event;
while (keep_running) {
XNextEvent(display, &event);
switch(event.type) {
case ClientMessage:
if (event.xclient.message_type == XInternAtom(display, "WM_PROTOCOLS", 1) && (Atom)event.xclient.data.l[0] == XInternAtom(display, "WM_DELETE_WINDOW", 1))
keep_running = 0;
break;
default:
break;
}
}
XDestroyWindow(display, win);
XCloseDisplay(display);
return 0;
}