Upstream oodles of Chrome for Android code into Chromium.

chrome/android/java_staging/src/org/chromium/chrome/browser/enhancedbookmarks/EnhancedBookmarkLoadingView.java

+// 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.chrome.browser.enhancedbookmarks;
+
+import android.animation.Animator;
+import android.animation.AnimatorListenerAdapter;
+import android.content.Context;
+import android.util.AttributeSet;
+import android.view.View;
+import android.widget.FrameLayout;
+import android.widget.ProgressBar;
+
+import com.google.android.apps.chrome.R;
+
+import org.chromium.ui.interpolators.BakedBezierInterpolator;
+
+/**
+ * View for showing loading content animation. The animation logic follows the Android loading
+ * content UI guideline.
+ */
+public class EnhancedBookmarkLoadingView extends FrameLayout {
+    private static final int LOADING_ANIMATION_DELAY_MS = 500;
+    private static final int MINIMUM_ANIMATION_SHOW_TIME_MS = 500;
+
+    private long mStartTime = -1;
+
+    private ProgressBar mLoadingProgressBar;
+
+    private final Runnable mDelayedShow = new Runnable() {
+        @Override
+        public void run() {
+            mStartTime = System.currentTimeMillis();
+            mLoadingProgressBar.setAlpha(1.0f);
+            mLoadingProgressBar.setVisibility(View.VISIBLE);
+        }
+    };
+
+    // Material loading design spec requires us to show progress spinner at least 500ms, so we need
+    // this delayed runnable to implement that.
+    private final Runnable mDelayedHide = new Runnable() {
+        @Override
+        public void run() {
+            animate().alpha(0.0f).setInterpolator(BakedBezierInterpolator.TRANSFORM_CURVE)
+                    .setListener(new AnimatorListenerAdapter() {
+                        @Override
+                        public void onAnimationEnd(Animator animation) {
+                            setVisibility(GONE);
+                        }
+                    });
+        }
+    };
+
+    /**
+     * Constructor for inflating from XML.
+     */
+    public EnhancedBookmarkLoadingView(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    @Override
+    protected void onFinishInflate() {
+        super.onFinishInflate();
+        mLoadingProgressBar = (ProgressBar) findViewById(R.id.eb_loading_circle);
+    }
+
+    /**
+     * Show loading UI. It shows the loading animation 500ms after.
+     */
+    public void showLoadingUI() {
+        removeCallbacks(mDelayedShow);
+        removeCallbacks(mDelayedHide);
+
+        setVisibility(VISIBLE);
+        setAlpha(1.0f);
+        mLoadingProgressBar.setVisibility(GONE);
+
+        postDelayed(mDelayedShow, LOADING_ANIMATION_DELAY_MS);
+    }
+
+    /**
+     * Hide loading UI. If progress bar is not shown, it disappears immediately. If so, it smoothly
+     * fades out.
+     */
+    public void hideLoadingUI() {
+        removeCallbacks(mDelayedShow);
+        removeCallbacks(mDelayedHide);
+
+        if (mLoadingProgressBar.getVisibility() == VISIBLE) {
+            postDelayed(mDelayedHide, Math.max(0,
+                    mStartTime + MINIMUM_ANIMATION_SHOW_TIME_MS - System.currentTimeMillis()));
+        } else {
+            setVisibility(GONE);
+        }
+    }
+}