transport selection refactor

Closes #1724
// FREEBIE

src/org/thoughtcrime/securesms/components/SendButton.java

@@ -0,0 +1,90 @@
+package org.thoughtcrime.securesms.components;
+
+import android.content.Context;
+import android.text.Spannable;
+import android.text.SpannableString;
+import android.text.style.RelativeSizeSpan;
+import android.util.AttributeSet;
+import android.view.View;
+import android.widget.EditText;
+import android.widget.ImageButton;
+
+import org.thoughtcrime.securesms.TransportOption;
+import org.thoughtcrime.securesms.TransportOptions;
+import org.thoughtcrime.securesms.TransportOptions.OnTransportChangedListener;
+
+public class SendButton extends ImageButton {
+  private TransportOptions transportOptions;
+  private EditText         composeText;
+
+  @SuppressWarnings("unused")
+  public SendButton(Context context) {
+    super(context);
+    initialize();
+  }
+
+  @SuppressWarnings("unused")
+  public SendButton(Context context, AttributeSet attrs) {
+    super(context, attrs);
+    initialize();
+  }
+
+  @SuppressWarnings("unused")
+  public SendButton(Context context, AttributeSet attrs, int defStyle) {
+    super(context, attrs, defStyle);
+    initialize();
+  }
+
+  private void initialize() {
+    transportOptions = new TransportOptions(getContext());
+    transportOptions.setOnTransportChangedListener(new OnTransportChangedListener() {
+      @Override
+      public void onChange(TransportOption newTransport) {
+        setImageResource(newTransport.drawable);
+        setContentDescription(newTransport.composeHint);
+        if (composeText != null) setComposeTextHint(newTransport.composeHint);
+      }
+    });
+
+    setOnLongClickListener(new OnLongClickListener() {
+      @Override
+      public boolean onLongClick(View view) {
+        if (transportOptions.getEnabledTransports().size() > 1) {
+          transportOptions.showPopup(SendButton.this);
+          return true;
+        }
+        return false;
+      }
+    });
+  }
+
+  public void setComposeTextView(EditText composeText) {
+    this.composeText = composeText;
+  }
+
+  public TransportOption getSelectedTransport() {
+    return transportOptions.getSelectedTransport();
+  }
+
+  public void initializeAvailableTransports(boolean isMediaMessage) {
+    transportOptions.initializeAvailableTransports(isMediaMessage);
+  }
+
+  public void disableTransport(String transport) {
+    transportOptions.disableTransport(transport);
+  }
+
+  public void setDefaultTransport(String transport) {
+    transportOptions.setDefaultTransport(transport);
+  }
+
+  private void setComposeTextHint(String hint) {
+    if (hint == null) {
+      this.composeText.setHint(null);
+    } else {
+      SpannableString span = new SpannableString(hint);
+      span.setSpan(new RelativeSizeSpan(0.8f), 0, hint.length(), Spannable.SPAN_INCLUSIVE_INCLUSIVE);
+      this.composeText.setHint(span);
+    }
+  }
+}