Add a basic UI to the Android Blimp client.

blimp/client/android/java/src/org/chromium/blimp/toolbar/Toolbar.java

Index: blimp/client/android/java/src/org/chromium/blimp/toolbar/Toolbar.java
diff --git a/blimp/client/android/java/src/org/chromium/blimp/toolbar/Toolbar.java b/blimp/client/android/java/src/org/chromium/blimp/toolbar/Toolbar.java
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index 0000000000000000000000000000000000000000..ca82caa0c233c56600cc41ebc51701c22a14cbcf
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+++ b/blimp/client/android/java/src/org/chromium/blimp/toolbar/Toolbar.java
@@ -0,0 +1,137 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.blimp.toolbar;
+
+import android.content.Context;
+import android.graphics.Bitmap;
+import android.text.TextUtils;
+import android.util.AttributeSet;
+import android.view.View;
+import android.widget.ImageButton;
+import android.widget.LinearLayout;
+
+import org.chromium.base.annotations.CalledByNative;
+import org.chromium.base.annotations.JNINamespace;
+
+import org.chromium.blimp.R;
+
+/**
+ * A {@link View} that visually represents the Blimp toolbar, which lets users issue navigation
+ * commands and displays relevant navigation UI.
+ */
+@JNINamespace("blimp")
+public class Toolbar extends LinearLayout implements UrlBar.UrlBarObserver,
+        View.OnClickListener {
+    private long mNativeToolbarPtr;
+
+    private UrlBar mUrlBar;
+    private ImageButton mReloadButton;
+
+    /**
+     * A URL to load when this object is initialized.  This handles the case where there is a URL
+     * to load before native is ready to receive any URL.
+     * */
+    private String mUrlToLoad;
+
+    /**
+     * Builds a new {@link Toolbar}.
+     * @param context A {@link Context} instance.
+     * @param attrs   An {@link AttributeSet} instance.
+     */
+    public Toolbar(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    /**
+     * To be called when the native library is loaded so that this class can initialize its native
+     * components.
+     */
+    public void initialize() {
+        assert mNativeToolbarPtr == 0;
+
+        mNativeToolbarPtr = nativeInit();
+        sendUrlTextInternal(mUrlToLoad);
+    }
+
+    /**
+     * To be called when this class should be torn down.  This {@link View} should not be used after
+     * this.
+     */
+    public void destroy() {
+        if (mNativeToolbarPtr != 0) {
+            nativeDestroy(mNativeToolbarPtr);
+            mNativeToolbarPtr = 0;
+        }
+    }
+
+    /**
+     * Loads {@code text} as if it had been typed by the user.  Useful for specifically loading
+     * startup URLs or testing.
+     * @param text The URL or text to load.
+     */
+    public void loadUrl(String text) {
+        mUrlBar.setText(text);
+        sendUrlTextInternal(text);
+    }
+
+    /**
+     * To be called when the user triggers a back navigation action.
+     * @return Whether or not the back event was consumed.
+     */
+    public boolean onBackPressed() {
+        if (mNativeToolbarPtr == 0) return false;
+        return nativeOnBackPressed(mNativeToolbarPtr);
+    }
+
+    // View overrides.
+    @Override
+    protected void onFinishInflate() {
+        super.onFinishInflate();
+
+        mUrlBar = (UrlBar) findViewById(R.id.toolbar_url_bar);
+        mUrlBar.addUrlBarObserver(this);
+
+        mReloadButton = (ImageButton) findViewById(R.id.toolbar_reload_btn);
+        mReloadButton.setOnClickListener(this);
+    }
+
+    // UrlBar.UrlBarObserver interface.
+    @Override
+    public void onNewTextEntered(String text) {
+        sendUrlTextInternal(text);
+    }
+
+    // View.OnClickListener interface.
+    @Override
+    public void onClick(View view) {
+        if (mNativeToolbarPtr == 0) return;
+        if (view == mReloadButton) nativeOnReloadPressed(mNativeToolbarPtr);
+    }
+
+    private void sendUrlTextInternal(String text) {
+        mUrlToLoad = null;
+        if (TextUtils.isEmpty(text)) return;
+
+        if (mNativeToolbarPtr == 0) {
+            mUrlToLoad = text;
+            return;
+        }
+
+        nativeOnUrlTextEntered(mNativeToolbarPtr, text);
+    }
+
+    // Methods that are called by native via JNI.
+    @CalledByNative
+    private void onNavigationStateChanged(String url, Bitmap favicon, String title) {
+        if (url != null) mUrlBar.setText(url);
+        // TODO(dtrainor): Add a UI for favicon and title data and tie it in here.
+    }
+
+    private native long nativeInit();
+    private native void nativeDestroy(long nativeToolbar);
+    private native void nativeOnUrlTextEntered(long nativeToolbar, String text);
+    private native void nativeOnReloadPressed(long nativeToolbar);
+    private native boolean nativeOnBackPressed(long nativeToolbar);
+}