Implement new media send flow.

Update our media send flow to allow users to send multiple images/videos
at once. This change includes:

- New in-app media picker flow.
- Ability to caption images and videos.
- Image editing tools are made more prominent in the flow.
- Some fixes to the image editing tools.

src/org/thoughtcrime/securesms/util/MediaUtil.java

@@ -239,6 +239,8 @@ public class MediaUtil {
 
     if ("com.android.providers.media.documents".equals(uri.getAuthority())) {
       return uri.getLastPathSegment().contains("video");
+    } else if (uri.toString().startsWith(MediaStore.Video.Media.EXTERNAL_CONTENT_URI.toString())) {
+      return true;
     }
 
     return false;
@@ -248,6 +250,13 @@ public class MediaUtil {
     if ("com.android.providers.media.documents".equals(uri.getAuthority())) {
       long videoId = Long.parseLong(uri.getLastPathSegment().split(":")[1]);
 
+      return MediaStore.Video.Thumbnails.getThumbnail(context.getContentResolver(),
+                                                      videoId,
+                                                      MediaStore.Images.Thumbnails.MINI_KIND,
+                                                      null);
+    } else if (uri.toString().startsWith(MediaStore.Video.Media.EXTERNAL_CONTENT_URI.toString())) {
+      long videoId = Long.parseLong(uri.getLastPathSegment());
+
       return MediaStore.Video.Thumbnails.getThumbnail(context.getContentResolver(),
                                                       videoId,
                                                       MediaStore.Images.Thumbnails.MINI_KIND,

src/org/thoughtcrime/securesms/util/ThemeUtil.java

@@ -5,7 +5,11 @@ import android.content.res.Resources;
 import android.graphics.Color;
 import android.support.annotation.AttrRes;
 import android.support.annotation.NonNull;
+import android.support.annotation.StyleRes;
+import android.support.v7.view.ContextThemeWrapper;
 import android.util.TypedValue;
+import android.view.LayoutInflater;
+import android.view.View;
 
 import org.thoughtcrime.securesms.R;
 
@@ -25,6 +29,11 @@ public class ThemeUtil {
     return Color.RED;
   }
 
+  public static LayoutInflater getThemedInflater(@NonNull Context context, @NonNull LayoutInflater inflater, @StyleRes int theme) {
+    Context contextThemeWrapper = new ContextThemeWrapper(context, theme);
+    return inflater.cloneInContext(contextThemeWrapper);
+  }
+
   private static String getAttribute(Context context, int attribute, String defaultValue) {
     TypedValue outValue = new TypedValue();
 

src/org/thoughtcrime/securesms/util/Util.java

@@ -133,6 +133,10 @@ public class Util {
     return value == null || value.getText() == null || TextUtils.isEmpty(value.getTextTrimmed());
   }
 
+  public static boolean isEmpty(Collection collection) {
+    return collection == null || collection.isEmpty();
+  }
+
   public static <K, V> V getOrDefault(@NonNull Map<K, V> map, K key, V defaultValue) {
     return map.containsKey(key) ? map.get(key) : defaultValue;
   }