void destroy() {
int xDisplay = device.xDisplay;
int pixel = handle.pixel;
if (device.colorRefCount != null) {
/* If this was the last reference, remove the color from the list */
if (--device.colorRefCount[pixel] == 0) {
device.xcolors[pixel] = null;
}
}
int colormap = OS.XDefaultColormap(xDisplay, OS.XDefaultScreen(xDisplay));
OS.XFreeColors(xDisplay, colormap, new int[] {pixel}, 1, 0);
handle = null;
}
void init(int red, int green, int blue) {
if ((red > 255) || (red < 0) || (green > 255) || (green < 0) || (blue > 255) || (blue < 0)) {
SWT.error(SWT.ERROR_INVALID_ARGUMENT);
}
XColor xColor = new XColor();
xColor.red = (short) ((red & 0xFF) | ((red & 0xFF) << 8));
xColor.green = (short) ((green & 0xFF) | ((green & 0xFF) << 8));
xColor.blue = (short) ((blue & 0xFF) | ((blue & 0xFF) << 8));
handle = xColor;
int xDisplay = device.xDisplay;
int screen = OS.XDefaultScreen(xDisplay);
int colormap = OS.XDefaultColormap(xDisplay, screen);
/* 1. Try to allocate the color */
if (OS.XAllocColor(xDisplay, colormap, xColor) != 0) {
if (device.colorRefCount != null) {
/* Make a copy of the color to put in the colors array */
XColor colorCopy = new XColor();
colorCopy.red = xColor.red;
colorCopy.green = xColor.green;
colorCopy.blue = xColor.blue;
colorCopy.pixel = xColor.pixel;
device.xcolors[colorCopy.pixel] = colorCopy;
device.colorRefCount[xColor.pixel]++;
}
return;
}
/*
* 2. Allocation failed. Query the entire colormap and
* find the closest match which can be allocated.
* This should never occur on a truecolor display.
*/
Visual visual = new Visual();
OS.memmove(visual, OS.XDefaultVisual(xDisplay, screen), Visual.sizeof);
int mapEntries = visual.map_entries;
XColor[] queried = new XColor[mapEntries];
int[] distances = new int[mapEntries];
/*
* Query all colors in the colormap and calculate the distance
* from each to the desired color.
*/
for (int i = 0; i < mapEntries; i++) {
XColor color = new XColor();
color.pixel = i;
queried[i] = color;
OS.XQueryColor(xDisplay, colormap, color);
int r = red - ((color.red >> 8) & 0xFF);
int g = green - ((color.green >> 8) & 0xFF);
int b = blue - ((color.blue >> 8) & 0xFF);
distances[i] = r * r + g * g + b * b;
}
/*
* Try to allocate closest matching queried color.
* The allocation can fail if the closest matching
* color is allocated privately, so go through them
* in order of increasing distance.
*/
for (int i = 0; i < mapEntries; i++) {
int minDist = 0x30000;
int minIndex = 0;
for (int j = 0; j < mapEntries; j++) {
if (distances[j] < minDist) {
minDist = distances[j];
minIndex = j;
}
}
XColor queriedColor = queried[minIndex];
XColor osColor = new XColor();
osColor.red = queriedColor.red;
osColor.green = queriedColor.green;
osColor.blue = queriedColor.blue;
if (OS.XAllocColor(xDisplay, colormap, osColor) != 0) {
/* Allocation succeeded. Copy the fields into the handle */
xColor.red = osColor.red;
xColor.green = osColor.green;
xColor.blue = osColor.blue;
xColor.pixel = osColor.pixel;
if (device.colorRefCount != null) {
/* Put osColor in the colors array */
device.xcolors[osColor.pixel] = osColor;
device.colorRefCount[osColor.pixel]++;
}
return;
}
/* The allocation failed; matching color is allocated privately */
distances[minIndex] = 0x30000;
}
/*
* 3. Couldn't allocate any of the colors in the colormap.
* This means all colormap entries were allocated privately
* by other applications. Give up and allocate black.
*/
XColor osColor = new XColor();
OS.XAllocColor(xDisplay, colormap, osColor);
/* Copy the fields into the handle */
xColor.red = osColor.red;
xColor.green = osColor.green;
xColor.blue = osColor.blue;
xColor.pixel = osColor.pixel;
if (device.colorRefCount != null) {
/* Put osColor in the colors array */
device.xcolors[osColor.pixel] = osColor;
device.colorRefCount[osColor.pixel]++;
}
}