lazily initialize emoji drawer

Saves a good amount of inflation time in onCreate for new conversations.

Closes #2585
Closes #2636

// FREEBIE

res/layout/conversation_activity.xml

@@ -122,11 +122,10 @@
         </LinearLayout>
     </RelativeLayout>
 
-    <org.thoughtcrime.securesms.components.EmojiDrawer
+    <ViewStub android:id="@+id/emoji_drawer_stub"
-            android:id="@+id/emoji_drawer"
+              android:inflatedId="@+id/emoji_drawer"
-            android:visibility="gone"
+              android:layout="@layout/emoji_drawer_stub"
-            android:layout_weight="1.1"
+              android:layout_width="match_parent"
-            android:layout_width="fill_parent"
+              android:layout_height="wrap_content" />
-            android:layout_height="wrap_content"/>
 
 </LinearLayout>

res/layout/emoji_drawer_stub.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<org.thoughtcrime.securesms.components.EmojiDrawer
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:layout_weight="1.1" />

src/org/thoughtcrime/securesms/ConversationActivity.java

@@ -43,6 +43,7 @@ import android.view.View;
 import android.view.View.OnClickListener;
 import android.view.View.OnFocusChangeListener;
 import android.view.View.OnKeyListener;
+import android.view.ViewStub;
 import android.view.inputmethod.EditorInfo;
 import android.view.inputmethod.InputMethodManager;
 import android.widget.TextView;
@@ -100,6 +101,7 @@ import org.thoughtcrime.securesms.util.ResUtil;
 import org.thoughtcrime.securesms.util.TextSecurePreferences;
 import org.thoughtcrime.securesms.util.Util;
 import org.whispersystems.libaxolotl.InvalidMessageException;
+import org.whispersystems.libaxolotl.util.guava.Optional;
 
 import java.io.IOException;
 import java.security.NoSuchAlgorithmException;
@@ -149,7 +151,7 @@ public class ConversationActivity extends PassphraseRequiredActionBarActivity
   private AttachmentManager             attachmentManager;
   private BroadcastReceiver             securityUpdateReceiver;
   private BroadcastReceiver             groupUpdateReceiver;
-  private EmojiDrawer                   emojiDrawer;
+  private Optional<EmojiDrawer>         emojiDrawer;
   private EmojiToggle                   emojiToggle;
 
   private Recipients recipients;
@@ -321,8 +323,8 @@ public class ConversationActivity extends PassphraseRequiredActionBarActivity
 
   @Override
   public void onBackPressed() {
-    if (emojiDrawer.getVisibility() == View.VISIBLE) {
+    if (emojiDrawer.isPresent() && emojiDrawer.get().getVisibility() == View.VISIBLE) {
-      emojiDrawer.setVisibility(View.GONE);
+      emojiDrawer.get().setVisibility(View.GONE);
       emojiToggle.toggle();
     } else {
       super.onBackPressed();
@@ -686,7 +688,7 @@ public class ConversationActivity extends PassphraseRequiredActionBarActivity
     sendButton     = (SendButton)  findViewById(R.id.send_button);
     composeText    = (ComposeText) findViewById(R.id.embedded_text_editor);
     charactersLeft = (TextView)    findViewById(R.id.space_left);
-    emojiDrawer    = (EmojiDrawer) findViewById(R.id.emoji_drawer);
+    emojiDrawer    = Optional.absent();
     emojiToggle    = (EmojiToggle) findViewById(R.id.emoji_toggle);
 
     if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
@@ -714,10 +716,15 @@ public class ConversationActivity extends PassphraseRequiredActionBarActivity
     composeText.setOnEditorActionListener(sendButtonListener);
     composeText.setOnClickListener(composeKeyPressedListener);
     composeText.setOnFocusChangeListener(composeKeyPressedListener);
-    emojiDrawer.setComposeEditText(composeText);
     emojiToggle.setOnClickListener(new EmojiToggleListener());
   }
 
+  private EmojiDrawer initializeEmojiDrawer() {
+    EmojiDrawer emojiDrawer = (EmojiDrawer)((ViewStub)findViewById(R.id.emoji_drawer_stub)).inflate();
+    emojiDrawer.setComposeEditText(composeText);
+    return emojiDrawer;
+  }
+
   private void initializeResources() {
     recipients       = RecipientFactory.getRecipientsForIds(this, getIntent().getLongArrayExtra(RECIPIENTS_EXTRA), true);
     threadId         = getIntent().getLongExtra(THREAD_ID_EXTRA, -1);
@@ -1101,13 +1108,16 @@ public class ConversationActivity extends PassphraseRequiredActionBarActivity
     public void onClick(View v) {
       InputMethodManager input = (InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
 
-      if (emojiDrawer.isOpen()) {
+      if (emojiDrawer.isPresent() && emojiDrawer.get().isOpen()) {
         input.showSoftInput(composeText, 0);
-        emojiDrawer.hide();
+        emojiDrawer.get().hide();
       } else {
+        if (!emojiDrawer.isPresent()) {
+          emojiDrawer = Optional.of(initializeEmojiDrawer());
+        }
         input.hideSoftInputFromWindow(composeText.getWindowToken(), 0);
 
-        emojiDrawer.show();
+        emojiDrawer.get().show();
       }
     }
   }
@@ -1146,7 +1156,7 @@ public class ConversationActivity extends PassphraseRequiredActionBarActivity
 
     @Override
     public void onClick(View v) {
-      if (emojiDrawer.isOpen()) {
+      if (emojiDrawer.isPresent() && emojiDrawer.get().isOpen()) {
         emojiToggle.performClick();
       }
     }
@@ -1162,7 +1172,7 @@ public class ConversationActivity extends PassphraseRequiredActionBarActivity
 
     @Override
     public void onFocusChange(View v, boolean hasFocus) {
-      if (hasFocus && emojiDrawer.isOpen()) {
+      if (hasFocus && emojiDrawer.isPresent() && emojiDrawer.get().isOpen()) {
         emojiToggle.performClick();
       }
     }