Java tutorial
/* This file is part of the Diaspora for Android. Diaspora for Android 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. Diaspora for Android 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 the Diaspora for Android. If not, see <http://www.gnu.org/licenses/>. */ package com.github.dfa.diaspora_android.ui; import android.content.Context; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.ColorFilter; import android.graphics.Paint; import android.graphics.PixelFormat; import android.graphics.Rect; import android.graphics.Typeface; import android.graphics.drawable.Drawable; import android.graphics.drawable.LayerDrawable; import android.support.v4.content.ContextCompat; import com.github.dfa.diaspora_android.R; import com.github.dfa.diaspora_android.util.AppSettings; public class BadgeDrawable extends Drawable { // Source: http://mobikul.com/adding-badge-count-on-menu-items-like-cart-notification-etc/ private static final String BADGE_VALUE_OVERFLOW = "*"; private Paint badgeBackground; private Paint badgeStroke; private Paint badgeText; private Rect textRect = new Rect(); private String badgeValue = ""; private boolean shouldDraw; public BadgeDrawable(Context context) { float textSize = context.getResources().getDimension(R.dimen.textsize_badge_count); AppSettings settings = new AppSettings(context); badgeBackground = new Paint(); badgeBackground.setColor(settings.getAccentColor()); badgeBackground.setAntiAlias(true); badgeBackground.setStyle(Paint.Style.FILL); badgeStroke = new Paint(); badgeStroke.setColor(ContextCompat.getColor(context.getApplicationContext(), R.color.colorPrimaryDark)); badgeStroke.setAntiAlias(true); badgeStroke.setStyle(Paint.Style.FILL); badgeText = new Paint(); badgeText.setColor(Color.WHITE); badgeText.setTypeface(Typeface.DEFAULT); badgeText.setTextSize(textSize); badgeText.setAntiAlias(true); badgeText.setTextAlign(Paint.Align.CENTER); } @Override public void draw(Canvas canvas) { if (!shouldDraw) { return; } Rect bounds = getBounds(); float width = bounds.right - bounds.left; float height = bounds.bottom - bounds.top; // Position the badge in the top-right quadrant of the icon. float radius = ((Math.max(width, height) / 2)) / 2; float centerX = (width - radius - 1) + 5; float centerY = radius - 5; if (badgeValue.length() <= 2) { // Draw badge circle. canvas.drawCircle(centerX, centerY, (int) (radius + 7.5), badgeStroke); canvas.drawCircle(centerX, centerY, (int) (radius + 5.5), badgeBackground); } else { canvas.drawCircle(centerX, centerY, (int) (radius + 8.5), badgeStroke); canvas.drawCircle(centerX, centerY, (int) (radius + 6.5), badgeBackground); //canvas.drawRoundRect(radius, radius, radius, radius, 10, 10, badgeBackground); } // Draw badge count message inside the circle. badgeText.getTextBounds(badgeValue, 0, badgeValue.length(), textRect); float textHeight = textRect.bottom - textRect.top; float textY = centerY + (textHeight / 2f); if (badgeValue.length() > 2) canvas.drawText(BADGE_VALUE_OVERFLOW, centerX, textY, badgeText); else canvas.drawText(badgeValue, centerX, textY, badgeText); } /* Sets the count (i.e notifications) to display. */ public void setCount(String count) { badgeValue = count; // Only draw a badge if there are notifications. shouldDraw = !count.equalsIgnoreCase("0"); invalidateSelf(); } @Override public void setAlpha(int alpha) { // do nothing } @Override public void setColorFilter(ColorFilter cf) { // do nothing } @Override public int getOpacity() { return PixelFormat.UNKNOWN; } public static void setBadgeCount(Context context, LayerDrawable icon, Integer count) { setBadgeCount(context, icon, count.toString()); } public static void setBadgeCount(Context context, LayerDrawable icon, String count) { BadgeDrawable badge; // Reuse drawable if possible Drawable reuse = icon.findDrawableByLayerId(R.id.ic_badge); if (reuse != null && reuse instanceof BadgeDrawable) { badge = (BadgeDrawable) reuse; } else { badge = new BadgeDrawable(context); } badge.setCount(count); icon.mutate(); icon.setDrawableByLayerId(R.id.ic_badge, badge); } }