rubberband.c

定要上载质量高而定要上载质量高而定要上载质量高而定要上载质量高而定要上载质量高而

#include <jni.h>
#include "org_flexdock_docking_drag_outline_xlib_XlibRubberBand.h"
#include <X11/Xlib.h>
#include <stdio.h>

struct xScreen {
    Display* display;
    Window window;
    int index;
    GC gc;
    int err;
} screen;

JNIEXPORT void JNICALL Java_org_flexdock_docking_drag_outline_xlib_XlibRubberBand_drawRectangle
        (JNIEnv *env, jobject obj, jint x, jint y, jint width, jint height) {
    drawRectImpl(x, y, width, height);
}

JNIEXPORT void JNICALL Java_org_flexdock_docking_drag_outline_xlib_XlibRubberBand_clearRectangle
        (JNIEnv *env, jobject obj, jint x, jint y, jint width, jint height) {
    drawRectImpl(x, y, width, height);
}


int drawRectImpl(int x, int y, int width, int height) {
    if(screen.err)
        return -1;

    if(!screen.display) {
        initialize();
        if(screen.err) {
            (void) fprintf(stderr, "cannot connect to X server %s\n", XDisplayName(NULL));
            return -1;
        }
    }

    if(width<0 || height<0)
        return -1;

    XSetForeground(screen.display, screen.gc, WhitePixel(screen.display, screen.index));
    XSetSubwindowMode(screen.display, screen.gc, IncludeInferiors);
    XSetFunction(screen.display, screen.gc, GXxor);
    XDrawRectangle(screen.display, screen.window, screen.gc, x, y, width, height);
    XFlush(screen.display);
    return 0;
}

int initialize() {
    if(screen.display)
        return -1;

    screen.display = screen.display=XOpenDisplay("");
    if(!screen.display) {
        screen.err = 1;
        return -1;
    }

    screen.index = XDefaultScreen(screen.display);
    screen.window = XDefaultRootWindow(screen.display);
    screen.gc = XCreateGC(screen.display, screen.window, 0, NULL);
    screen.err = 0;
    return 0;
}




JNIEXPORT void JNICALL Java_org_flexdock_docking_drag_outline_xlib_XlibRubberBand_cleanup
        (JNIEnv *env, jobject obj) {
    cleanupImpl();
}

JNIEXPORT void JNICALL JNI_OnUnload(JavaVM *vm, void *reserved) {
	cleanupImpl();
}

int cleanupImpl() {
    if(screen.display)
        XCloseDisplay(screen.display);
    return 0;
}