/*
* Firetweet - Twitter client for Android
*
* Copyright (C) 2012-2015 Mariotaku Lee <mariotaku.lee@gmail.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.getlantern.firetweet.util;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
/**
* Created by mariotaku on 15/1/8.
*/
public class ColorUtils {
public static Bitmap getColorPreviewBitmap(final Context context, final int color, final boolean border) {
if (context == null) return null;
final float density = context.getResources().getDisplayMetrics().density;
final int width = (int) (32 * density), height = (int) (32 * density);
final Bitmap bm = Bitmap.createBitmap(width, height, Config.ARGB_8888);
final Canvas canvas = new Canvas(bm);
final int rectrangleSize = (int) (density * 5);
final int numRectanglesHorizontal = (int) Math.ceil(width / rectrangleSize);
final int numRectanglesVertical = (int) Math.ceil(height / rectrangleSize);
final Rect r = new Rect();
boolean verticalStartWhite = true;
for (int i = 0; i <= numRectanglesVertical; i++) {
boolean isWhite = verticalStartWhite;
for (int j = 0; j <= numRectanglesHorizontal; j++) {
r.top = i * rectrangleSize;
r.left = j * rectrangleSize;
r.bottom = r.top + rectrangleSize;
r.right = r.left + rectrangleSize;
final Paint paint = new Paint();
paint.setColor(isWhite ? Color.WHITE : Color.GRAY);
canvas.drawRect(r, paint);
isWhite = !isWhite;
}
verticalStartWhite = !verticalStartWhite;
}
canvas.drawColor(color);
if (border) {
final Paint paint = new Paint();
paint.setColor(Color.WHITE);
paint.setStrokeWidth(1f * density);
final float[] points = new float[]{0, 0, width, 0, 0, 0, 0, height, width, 0, width, height, 0, height,
width, height};
canvas.drawLines(points, paint);
}
return bm;
}
public static int getYIQLuminance(int color) {
final int r = Color.red(color), g = Color.green(color), b = Color.blue(color);
return (r * 299 + g * 587 + b * 114) / 1000;
}
public static void colorToYIQ(int color, int[] yiq) {
final int r = Color.red(color), g = Color.green(color), b = Color.blue(color);
yiq[0] = (r * 299 + g * 587 + b * 114) / 1000;
yiq[1] = (r * 596 - g * 275 - b * 321) / 1000;
yiq[2] = (r * 212 - g * 523 + b * 311) / 1000;
}
public static int YIQToColor(int alpha, int[] yiq) {
final int r = MathUtils.clamp((yiq[0] * 1000 + yiq[1] * 956 + yiq[2] * 620) / 1000, 0, 255);
final int g = MathUtils.clamp((yiq[0] * 1000 - yiq[1] * 272 - yiq[2] * 647) / 1000, 0, 255);
final int b = MathUtils.clamp((yiq[0] * 1000 - yiq[1] * 1108 + yiq[2] * 1705) / 1000, 0, 255);
return Color.argb(alpha, r, g, b);
}
public static int getContrastYIQ(int color, int colorDark, int colorLight) {
return getContrastYIQ(color, 128, colorDark, colorLight);
}
public static int getContrastYIQ(int color) {
return getContrastYIQ(color, 128);
}
public static int getContrastYIQ(int color, int threshold) {
return getContrastYIQ(color, threshold, Color.BLACK, Color.WHITE);
}
/**
* Get most contrasting color
*
* @param color Input color, alpha channel will be disposed.
* @return {@link android.graphics.Color#WHITE} or {@link android.graphics.Color#BLACK}
* @see <a href='http://24ways.org/2010/calculating-color-contrast/'>Calculating Color Contrast</a>
*/
public static int getContrastYIQ(int color, int threshold, int colorDark, int colorLight) {
final int r = Color.red(color), g = Color.green(color), b = Color.blue(color);
final int yiq = ((r * 299) + (g * 587) + (b * 114)) / 1000;
return (yiq >= threshold) ? colorDark : colorLight;
}
}