Add k-9 style avatars to group conversations

Closes #1107

res/values/arrays.xml

@@ -39,6 +39,20 @@
       <item>Ukrainian Український</item>
   </string-array>
 
+  <array name="avatar_colors">
+    <item>#6dcaec</item>
+    <item>#cf9fe7</item>
+    <item>#b6db49</item>
+    <item>#ffd060</item>
+    <item>#ff7979</item>
+
+    <item>#2cb1e1</item>
+    <item>#c182e0</item>
+    <item>#92c500</item>
+    <item>#ffb61c</item>
+    <item>#f83a3a</item>
+  </array>
+
   <string-array name="language_values">
       <item>zz</item>
       <item>en</item>

src/org/thoughtcrime/securesms/ConversationItem.java

@@ -22,6 +22,7 @@ import android.content.Context;
 import android.content.DialogInterface;
 import android.content.Intent;
 import android.content.res.TypedArray;
+import android.graphics.Bitmap;
 import android.graphics.Color;
 import android.graphics.drawable.ColorDrawable;
 import android.net.Uri;
@@ -40,6 +41,7 @@ import android.widget.Toast;
 
 import org.thoughtcrime.securesms.crypto.MasterSecret;
 import org.thoughtcrime.securesms.database.DatabaseFactory;
+import org.thoughtcrime.securesms.contacts.ContactPhotoFactory;
 import org.thoughtcrime.securesms.database.MmsDatabase;
 import org.thoughtcrime.securesms.database.SmsDatabase;
 import org.thoughtcrime.securesms.database.model.MediaMmsMessageRecord;
@@ -405,7 +407,15 @@ public class ConversationItem extends LinearLayout {
   private void setContactPhotoForRecipient(final Recipient recipient) {
     if (contactPhoto == null) return;
 
-    contactPhoto.setImageBitmap(recipient.getCircleCroppedContactPhoto());
+    Bitmap contactPhotoBitmap;
+
+    if ((recipient.getContactPhoto() == ContactPhotoFactory.getDefaultContactPhoto(context)) && (groupThread)) {
+      contactPhotoBitmap = recipient.getGeneratedAvatar(context);
+    } else {
+      contactPhotoBitmap = recipient.getCircleCroppedContactPhoto();
+    }
+
+    contactPhoto.setImageBitmap(contactPhotoBitmap);
 
     contactPhoto.setOnClickListener(new View.OnClickListener() {
       @Override

src/org/thoughtcrime/securesms/recipients/AvatarGenerator.java

@@ -0,0 +1,120 @@
+package org.thoughtcrime.securesms.recipients;
+
+import android.content.Context;
+import android.content.res.Resources;
+import android.content.res.TypedArray;
+import android.graphics.Bitmap;
+import android.graphics.Canvas;
+import android.graphics.Color;
+import android.graphics.Paint;
+import android.graphics.Rect;
+import android.graphics.Typeface;
+
+import org.thoughtcrime.securesms.R;
+import org.thoughtcrime.securesms.contacts.ContactPhotoFactory;
+import org.thoughtcrime.securesms.util.BitmapUtil;
+
+/**
+ * Utility class to generate avatars for contacts who don't have a contact
+ * picture set.
+ *
+ * @author Lukas Barth
+ */
+public class AvatarGenerator {
+
+  public static Bitmap generateFor(Context context, Recipient recipient) {
+    if ((recipient == null) || (recipient.getName() == null)) {
+      return BitmapUtil.getCircleCroppedBitmap(ContactPhotoFactory.getDefaultContactPhoto(context));
+    }
+
+    final int    size            = ContactPhotoFactory.getDefaultContactPhoto(context).getHeight();
+    final Bitmap output          = Bitmap.createBitmap(size, size, Bitmap.Config.ARGB_8888);
+    final Canvas canvas          = new Canvas(output);
+    final int    color           = getColorForRecipient(recipient, context);
+    final Paint  paint           = new Paint();
+    final int    innerRectOffset = (int) Math.ceil((size - Math.sqrt(2) * (size / 2)) / 2);
+    final Rect   innerRect       = new Rect(innerRectOffset, innerRectOffset,
+                                            size - innerRectOffset, size - innerRectOffset);
+
+    paint.setAntiAlias(true);
+    paint.setColor(color);
+    canvas.drawCircle(size / 2, size / 2, size / 2, paint);
+
+    paint.setColor(Color.WHITE);
+    Typeface robotoLightTypeface = Typeface.createFromAsset(context.getAssets(), "fonts/Roboto-Light.ttf");
+    paint.setTypeface(robotoLightTypeface);
+    setFontSize(innerRect, paint);
+
+    paint.setTextAlign(Paint.Align.CENTER);
+
+    int initialIndex = 0;
+    char[] contactName = recipient.getName().toCharArray();
+
+    if (contactName.length == 0) {
+      contactName = new char[]{'?'};
+      initialIndex = 0;
+    } else {
+      while ((! Character.isLetter(contactName[initialIndex]))) {
+        initialIndex ++;
+
+        if (initialIndex >= contactName.length) {
+          contactName[0] = '?';
+          initialIndex = 0;
+          break;
+        }
+      }
+    }
+
+    Rect textBounds = new Rect();
+    paint.getTextBounds(contactName, initialIndex, 1, textBounds);
+
+    int bottomOffset = (innerRect.height() - textBounds.height()) / 2;
+
+    canvas.drawText(Character.toString(contactName[initialIndex]),
+                    innerRect.centerX(), innerRect.bottom - bottomOffset, paint);
+
+    return output;
+  }
+
+
+  private static int getColorForRecipient(Recipient recipient, Context context) {
+    if ((recipient == null) || (recipient.getName() == null)) {
+      return Color.WHITE;
+    }
+
+    long       nameHash   = recipient.getName().hashCode();
+    Resources  res        = context.getResources();
+    TypedArray colorArray = res.obtainTypedArray(R.array.avatar_colors);
+    int        index      = Math.abs((int) (nameHash % colorArray.length()));
+    int        color      = colorArray.getColor(index, Color.BLACK);
+
+    colorArray.recycle();
+
+    return color;
+  }
+
+  private static int setFontSize(Rect textRect, Paint paint) {
+    boolean overflow = false;
+    int currentSize = 0;
+
+    while (!overflow) {
+      currentSize++;
+      paint.setTextSize(currentSize);
+
+      Paint.FontMetricsInt fontMetrics = paint.getFontMetricsInt();
+      int textHeight = fontMetrics.descent - fontMetrics.ascent;
+
+      if (textHeight > textRect.height()) {
+        overflow = true;
+      }
+    }
+
+    currentSize--;
+
+    currentSize *= 1.2;
+
+    paint.setTextSize(currentSize);
+
+    return currentSize;
+  }
+}

src/org/thoughtcrime/securesms/recipients/Recipient.java

@@ -54,6 +54,7 @@ public class Recipient implements Parcelable {
 
   private Bitmap contactPhoto;
   private Bitmap circleCroppedContactPhoto;
+  private Bitmap generatedAvatar;
 
   private Uri    contactUri;
 
@@ -64,6 +65,7 @@ public class Recipient implements Parcelable {
     this.circleCroppedContactPhoto  = circleCroppedContactPhoto;
     this.contactPhoto               = contactPhoto;
     this.recipientId                = recipientId;
+    this.generatedAvatar            = null;
 
     future.addListener(new FutureTaskListener<RecipientDetails>() {
       @Override
@@ -187,6 +189,13 @@ public class Recipient implements Parcelable {
     return this.circleCroppedContactPhoto;
   }
 
+  public synchronized Bitmap getGeneratedAvatar(Context context) {
+    if (this.generatedAvatar == null)
+      this.generatedAvatar = AvatarGenerator.generateFor(context, this);
+
+    return this.generatedAvatar;
+  }
+
   public static Recipient getUnknownRecipient(Context context) {
     return new Recipient("Unknown", "Unknown", -1, null,
                          ContactPhotoFactory.getDefaultContactPhoto(context),