Assign color to group members based on XEP-0392

More or less. Close #1122

Signed-off-by: Daniele Ricci <[email protected]>

app/src/androidTest/java/org/kontalk/util/XMPPUtilsTest.java

@@ -0,0 +1,33 @@
+/*
+ * Kontalk Android client
+ * Copyright (C) 2017 Kontalk Devteam <[email protected]>
+
+ * 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.kontalk.util;
+
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+
+public class XMPPUtilsTest {
+
+    @Test
+    public void testGetJIDColor() throws Exception {
+        assertEquals(0xff55ff00, XMPPUtils.getJIDColor("[email protected]"));
+    }
+
+}

app/src/main/java/org/kontalk/ui/view/BaseMessageTheme.java

@@ -34,6 +34,7 @@
 import org.kontalk.message.MessageComponent;
 import org.kontalk.message.TextComponent;
 import org.kontalk.provider.MyMessages;
+import org.kontalk.util.XMPPUtils;
 
 
 /**
@@ -133,6 +134,7 @@ public void setIncoming(Contact contact, boolean sameMessageBlock) {
         if (mGroupChat) {
             if (contact != null) {
                 mContactNameView.setText(contact.getDisplayName());
+                mContactNameView.setTextColor(XMPPUtils.getJIDColor(contact.getJID()));
                 mContactNameView.setVisibility(View.VISIBLE);
             }
             else {

app/src/main/java/org/kontalk/util/ConsistentColorGeneration.java

@@ -0,0 +1,105 @@
+/*
+ * Kontalk Android client
+ * Copyright (C) 2017 Kontalk Devteam <[email protected]>
+
+ * 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.kontalk.util;
+
+import org.jivesoftware.smack.util.SHA1;
+
+
+/**
+ * Implementation of XEP-0392: Consistent Color Generation<br>
+ * TODO this class is a brutal porting from JavaScript code and should be optimized
+ * @see <a href="https://xmpp.org/extensions/xep-0392.html">XEP-0392</a>
+ * @see <a href="https://github.com/jsxc/consistent-color-generation">Ported from JavaScript implementation</a>
+ */
+public class ConsistentColorGeneration {
+
+    public static final int CORRECTION_NONE = 0;
+    public static final int CORRECTION_REDGREEN = 1;
+    public static final int CORRECTION_BLUE = 2;
+
+    private static final double KR = 0.299;
+    private static final double KG = 0.587;
+    private static final double KB = 0.114;
+
+    private ConsistentColorGeneration() {}
+
+    public static double[] getRGB(String identifier, int correction) {
+        return getRGB(identifier, correction, 0.732);
+    }
+
+    public static double[] getRGB(String identifier, int correction, double y) {
+        double angle = generateAngle(identifier, correction);
+        double[] space = generateCbCr(angle);
+
+        return cbCrToRGB(space[0], space[1], y);
+    }
+
+    private static double[] generateCbCr(double angle) {
+        double cr = Math.sin(angle);
+        double cb = Math.cos(angle);
+        double factor;
+
+        if (Math.abs(cr) > Math.abs(cb)) {
+            factor = 0.5d / Math.abs(cr);
+        }
+        else {
+            factor = 0.5d / Math.abs(cb);
+        }
+
+        cb = cb * factor;
+        cr = cr * factor;
+
+        return new double[] { cb, cr };
+    }
+
+    private static double generateAngle(String identifier, int correction) {
+        String hash = SHA1.hex(identifier);
+        String first16bits = hash.substring(0, 4);
+        String littleEndian = first16bits.substring(2) + first16bits.substring(0, 2);
+        double angle = (double) Integer.parseInt(littleEndian, 16) / 65535 * 2 * Math.PI;
+
+        switch (correction) {
+            case CORRECTION_REDGREEN:
+                angle /= 2;
+                break;
+            case CORRECTION_BLUE:
+                angle = (angle / 2) + (Math.PI / 2);
+                break;
+        }
+
+        return angle;
+    }
+
+    private static double clipValueToRangeFrom0To1(double value) {
+        return Math.max(0, Math.min(value, 1));
+    }
+
+    private static double[] cbCrToRGB(double cb, double cr, double y) {
+        double r = 2 * (1 - KR) * cr + y;
+        double b = 2 * (1 - KB) * cb + y;
+        double g = (y - KR * r - KB * b) / KG;
+
+        return new double[] {
+            clipValueToRangeFrom0To1(r),
+            clipValueToRangeFrom0To1(g),
+            clipValueToRangeFrom0To1(b),
+        };
+    }
+
+}

app/src/main/java/org/kontalk/util/MessageUtils.java

@@ -277,7 +277,8 @@ public static String bytesToHex(byte[] data) {
         return buf.toString();
     }
 
-    /** TODO move somewhere else */
+    /** @deprecated Use {@link org.jivesoftware.smack.util.SHA1#hex(String)} */
+    @Deprecated
     public static String sha1(String text) {
         MessageDigest md = new SHA1.Digest();
         md.update(text.getBytes(), 0, text.length());

app/src/main/java/org/kontalk/util/XMPPUtils.java

@@ -33,6 +33,8 @@
 import org.xmlpull.v1.XmlPullParserFactory;
 
 import android.content.Context;
+import android.graphics.Color;
+import android.support.annotation.ColorInt;
 
 import org.kontalk.client.EndpointServer;
 
@@ -139,4 +141,20 @@ public static boolean isDomainJID(String jid) {
             .equalsIgnoreCase(jid);
     }
 
+    /**
+     * Returns a color for the given JID calculated with the rules of XEP-0392
+     * @see <a href="https://xmpp.org/extensions/xep-0392.html">XEP-0392</a>
+     */
+    @ColorInt
+    public static int getJIDColor(String jid) {
+        // TODO get correction from accessibility settings
+        double[] rgb = ConsistentColorGeneration.getRGB(jid,
+            ConsistentColorGeneration.CORRECTION_NONE);
+
+        return Color.argb(0xff,
+            (int) (rgb[0] * 255),
+            (int) (rgb[1] * 255),
+            (int) (rgb[2] * 255));
+    }
+
 }

app/src/main/res/layout/balloon_avatar_in.xml

@@ -25,6 +25,8 @@
     android:gravity="start">
 
     <TextView android:id="@+id/contact_name"
+        style="?android:attr/textAppearance"
+        android:textStyle="bold"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_marginTop="4dp"

app/src/test/java/org/kontalk/util/ConsistentColorGenerationTest.java

@@ -0,0 +1,45 @@
+/*
+ * Kontalk Android client
+ * Copyright (C) 2017 Kontalk Devteam <[email protected]>
+
+ * 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.kontalk.util;
+
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+
+public class ConsistentColorGenerationTest {
+
+    @Test
+    public void testGetRGB() throws Exception {
+        double[] rgb;
+
+        rgb = ConsistentColorGeneration.getRGB("[email protected]",
+            ConsistentColorGeneration.CORRECTION_NONE);
+        assertEquals(rgb[0], 0.337, 0.01);
+        assertEquals(rgb[1], 1.000, 0.01);
+        assertEquals(rgb[2], 0.000, 0.01);
+
+        rgb = ConsistentColorGeneration.getRGB("Romeo",
+            ConsistentColorGeneration.CORRECTION_NONE);
+        assertEquals(rgb[0], 0.281, 0.01);
+        assertEquals(rgb[1], 0.790, 0.01);
+        assertEquals(rgb[2], 1.000, 0.01);
+    }
+
+}