1 files changed, 160 insertions, 0 deletions
diff --git a/src/com/android/launcher3/BaseRecyclerViewFastScrollPopup.java b/src/com/android/launcher3/BaseRecyclerViewFastScrollPopup.java
new file mode 100644
index 000000000..aeeb5156d
--- /dev/null
+++ b/src/com/android/launcher3/BaseRecyclerViewFastScrollPopup.java
@@ -0,0 +1,160 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.launcher3;
+
+import android.animation.Animator;
+import android.animation.ObjectAnimator;
+import android.content.res.Resources;
+import android.graphics.Canvas;
+import android.graphics.Color;
+import android.graphics.Paint;
+import android.graphics.Rect;
+import android.graphics.drawable.Drawable;
+
+/**
+ * The fast scroller popup that shows the section name the list will jump to.
+ */
+public class BaseRecyclerViewFastScrollPopup {
+
+    private static final float FAST_SCROLL_OVERLAY_Y_OFFSET_FACTOR = 1.5f;
+
+    private Resources mRes;
+    private BaseRecyclerView mRv;
+
+    private Drawable mBg;
+    // The absolute bounds of the fast scroller bg
+    private Rect mBgBounds = new Rect();
+    private int mBgOriginalSize;
+    private Rect mInvalidateRect = new Rect();
+    private Rect mTmpRect = new Rect();
+
+    private String mSectionName;
+    private Paint mTextPaint;
+    private Rect mTextBounds = new Rect();
+    private float mAlpha;
+
+    private Animator mAlphaAnimator;
+    private boolean mVisible;
+
+    public BaseRecyclerViewFastScrollPopup(BaseRecyclerView rv, Resources res) {
+        mRes = res;
+        mRv = rv;
+        mBgOriginalSize = res.getDimensionPixelSize(R.dimen.container_fastscroll_popup_size);
+        mBg = res.getDrawable(R.drawable.container_fastscroll_popup_bg);
+        mBg.setBounds(0, 0, mBgOriginalSize, mBgOriginalSize);
+        mTextPaint = new Paint();
+        mTextPaint.setColor(Color.WHITE);
+        mTextPaint.setAntiAlias(true);
+        mTextPaint.setTextSize(res.getDimensionPixelSize(R.dimen.container_fastscroll_popup_text_size));
+    }
+
+    /**
+     * Sets the section name.
+     */
+    public void setSectionName(String sectionName) {
+        if (!sectionName.equals(mSectionName)) {
+            mSectionName = sectionName;
+            mTextPaint.getTextBounds(sectionName, 0, sectionName.length(), mTextBounds);
+            // Update the width to use measureText since that is more accurate
+            mTextBounds.right = (int) (mTextBounds.left + mTextPaint.measureText(sectionName));
+        }
+    }
+
+    /**
+     * Updates the bounds for the fast scroller.
+     * @return the invalidation rect for this update.
+     */
+    public Rect updateFastScrollerBounds(BaseRecyclerView rv, int lastTouchY) {
+        mInvalidateRect.set(mBgBounds);
+
+        if (isVisible()) {
+            // Calculate the dimensions and position of the fast scroller popup
+            int edgePadding = rv.getMaxScrollbarWidth();
+            int bgPadding = (mBgOriginalSize - mTextBounds.height()) / 2;
+            int bgHeight = mBgOriginalSize;
+            int bgWidth = Math.max(mBgOriginalSize, mTextBounds.width() + (2 * bgPadding));
+            if (Utilities.isRtl(mRes)) {
+                mBgBounds.left = rv.getBackgroundPadding().left + (2 * rv.getMaxScrollbarWidth());
+                mBgBounds.right = mBgBounds.left + bgWidth;
+            } else {
+                mBgBounds.right = rv.getWidth() - rv.getBackgroundPadding().right -
+                        (2 * rv.getMaxScrollbarWidth());
+                mBgBounds.left = mBgBounds.right - bgWidth;
+            }
+            mBgBounds.top = lastTouchY - (int) (FAST_SCROLL_OVERLAY_Y_OFFSET_FACTOR * bgHeight);
+            mBgBounds.top = Math.max(edgePadding,
+                    Math.min(mBgBounds.top, rv.getHeight() - edgePadding - bgHeight));
+            mBgBounds.bottom = mBgBounds.top + bgHeight;
+        } else {
+            mBgBounds.setEmpty();
+        }
+
+        // Combine the old and new fast scroller bounds to create the full invalidate rect
+        mInvalidateRect.union(mBgBounds);
+        return mInvalidateRect;
+    }
+
+    /**
+     * Animates the visibility of the fast scroller popup.
+     */
+    public void animateVisibility(boolean visible) {
+        if (mVisible != visible) {
+            mVisible = visible;
+            if (mAlphaAnimator != null) {
+                mAlphaAnimator.cancel();
+            }
+            mAlphaAnimator = ObjectAnimator.ofFloat(this, "alpha", visible ? 1f : 0f);
+            mAlphaAnimator.setDuration(visible ? 200 : 150);
+            mAlphaAnimator.start();
+        }
+    }
+
+    // Setter/getter for the popup alpha for animations
+    public void setAlpha(float alpha) {
+        mAlpha = alpha;
+        mRv.invalidate(mBgBounds);
+    }
+
+    public float getAlpha() {
+        return mAlpha;
+    }
+
+    public int getHeight() {
+        return mBgOriginalSize;
+    }
+
+    public void draw(Canvas c) {
+        if (isVisible()) {
+            // Draw the fast scroller popup
+            int restoreCount = c.save(Canvas.MATRIX_SAVE_FLAG);
+            c.translate(mBgBounds.left, mBgBounds.top);
+            mTmpRect.set(mBgBounds);
+            mTmpRect.offsetTo(0, 0);
+            mBg.setBounds(mTmpRect);
+            mBg.setAlpha((int) (mAlpha * 255));
+            mBg.draw(c);
+            mTextPaint.setAlpha((int) (mAlpha * 255));
+            c.drawText(mSectionName, (mBgBounds.width() - mTextBounds.width()) / 2,
+                    mBgBounds.height() - (mBgBounds.height() - mTextBounds.height()) / 2,
+                    mTextPaint);
+            c.restoreToCount(restoreCount);
+        }
+    }
+
+    public boolean isVisible() {
+        return (mAlpha > 0f) && (mSectionName != null);
+    }
+}