FloatingHeaderHandler refactored into custom view FloatingHeaderView.

No logical change.

Change-Id: I9a6dadb151872abe9915e96833af530ca08ddb8e

1 files changed, 233 insertions, 0 deletions

diff --git a/src/com/android/launcher3/allapps/FloatingHeaderView.java b/src/com/android/launcher3/allapps/FloatingHeaderView.java
new file mode 100644
index 000000000..39e681886
--- /dev/null
+++ b/src/com/android/launcher3/allapps/FloatingHeaderView.java
@@ -0,0 +1,233 @@
+/*
+ * Copyright (C) 2017 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.allapps;
+
+
+import android.animation.ValueAnimator;
+import android.content.Context;
+import android.content.res.Resources;
+import android.graphics.Rect;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.support.v7.widget.RecyclerView;
+import android.util.AttributeSet;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.RelativeLayout;
+
+import com.android.launcher3.R;
+
+public class FloatingHeaderView extends RelativeLayout implements
+        ValueAnimator.AnimatorUpdateListener {
+
+    private static final boolean SHOW_PREDICTIONS_ONLY_ON_TOP = true;
+
+    private final Rect mClip = new Rect(0, 0, Integer.MAX_VALUE, Integer.MAX_VALUE);
+    private final ValueAnimator mAnimator = ValueAnimator.ofInt(0, 0);
+    private final RecyclerView.OnScrollListener mOnScrollListener = new RecyclerView.OnScrollListener() {
+        @Override
+        public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
+            if (SHOW_PREDICTIONS_ONLY_ON_TOP) {
+                return;
+            }
+            if (!mTopOnlyMode && newState == RecyclerView.SCROLL_STATE_IDLE
+                    && mTranslationY != -mMaxTranslation && mTranslationY != 0) {
+                float scroll = Math.abs(getCurrentScroll());
+                boolean expand =  scroll > mMaxTranslation
+                        ? Math.abs(mTranslationY) < mMaxTranslation / 2 : true;
+                setExpanded(expand);
+            }
+        }
+
+        @Override
+        public void onScrolled(RecyclerView rv, int dx, int dy) {
+            boolean isMainRV = rv == mMainRV;
+            if (isMainRV != mMainRVActive) {
+                return;
+            }
+
+            if (mAnimator.isStarted()) {
+                mAnimator.cancel();
+            }
+
+            int current = - (isMainRV
+                    ? mMainRV.getCurrentScrollY()
+                    : mWorkRV.getCurrentScrollY());
+            moved(current);
+            apply();
+        }
+    };
+
+    private PredictionRowView mPredictionRow;
+    private ViewGroup mTabLayout;
+    private View mDivider;
+    private AllAppsRecyclerView mMainRV;
+    private AllAppsRecyclerView mWorkRV;
+    private boolean mTopOnlyMode;
+    private boolean mHeaderHidden;
+    private int mMaxTranslation;
+    private int mSnappedScrolledY;
+    private int mTranslationY;
+    private int mMainScrolledY;
+    private int mWorkScrolledY;
+    private boolean mMainRVActive;
+
+    public FloatingHeaderView(@NonNull Context context) {
+        this(context, null);
+    }
+
+    public FloatingHeaderView(@NonNull Context context, @Nullable AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    @Override
+    protected void onFinishInflate() {
+        super.onFinishInflate();
+        mTabLayout = findViewById(R.id.tabs);
+        mDivider = findViewById(R.id.divider);
+        mPredictionRow = findViewById(R.id.header_content);
+    }
+
+    public void setup(@NonNull AllAppsRecyclerView personalRV, @Nullable AllAppsRecyclerView workRV,
+                      int predictionRowHeight) {
+        mTopOnlyMode = workRV == null;
+        mTabLayout.setVisibility(mTopOnlyMode ? View.GONE : View.VISIBLE);
+        mPredictionRow.getLayoutParams().height = predictionRowHeight;
+        mMaxTranslation = predictionRowHeight;
+        mMainRV = setupRV(mMainRV, personalRV);
+        mWorkRV = setupRV(mWorkRV, workRV);
+        setMainActive(true);
+        setupDivider();
+    }
+
+    private AllAppsRecyclerView setupRV(AllAppsRecyclerView old, AllAppsRecyclerView updated) {
+        if (old != updated && updated != null ) {
+            updated.addOnScrollListener(mOnScrollListener);
+        }
+        return updated;
+    }
+
+    private void setupDivider() {
+        Resources res = getResources();
+        int verticalGap = res.getDimensionPixelSize(R.dimen.all_apps_divider_margin_vertical);
+        int sideGap = res.getDimensionPixelSize(R.dimen.dynamic_grid_edge_margin);
+        mDivider.setPadding(sideGap, verticalGap,sideGap, mTopOnlyMode ? verticalGap : 0);
+        RelativeLayout.LayoutParams lp = (RelativeLayout.LayoutParams) mDivider.getLayoutParams();
+        lp.removeRule(RelativeLayout.ALIGN_BOTTOM);
+        lp.addRule(RelativeLayout.ALIGN_BOTTOM, mTopOnlyMode ? R.id.header_content : R.id.tabs);
+        mDivider.setLayoutParams(lp);
+    }
+
+    public void setMainActive(boolean active) {
+        mMainRVActive = active;
+        mSnappedScrolledY = getCurrentScroll() - mMaxTranslation;
+        setExpanded(true);
+    }
+
+    public PredictionRowView getPredictionRow() {
+        return mPredictionRow;
+    }
+
+    public ViewGroup getTabLayout() {
+        return mTabLayout;
+    }
+
+    public View getDivider() {
+        return mDivider;
+    }
+
+    public void reset() {
+        mMainScrolledY = 0;
+        mWorkScrolledY = 0;
+        setExpanded(true);
+    }
+
+    private boolean canSnapAt(int currentScrollY) {
+        boolean snapOnlyOnTop = SHOW_PREDICTIONS_ONLY_ON_TOP || mTopOnlyMode;
+        return !snapOnlyOnTop || Math.abs(currentScrollY) <= mPredictionRow.getHeight();
+    }
+
+    private void moved(final int currentScrollY) {
+        if (mHeaderHidden) {
+            if (currentScrollY <= mSnappedScrolledY) {
+                if (canSnapAt(currentScrollY)) {
+                    mSnappedScrolledY = currentScrollY;
+                }
+            } else {
+                mHeaderHidden = false;
+            }
+            mTranslationY = currentScrollY;
+        } else if (!mHeaderHidden) {
+            mTranslationY = currentScrollY - mSnappedScrolledY - mMaxTranslation;
+
+            // update state vars
+            if (mTranslationY >= 0) { // expanded: must not move down further
+                mTranslationY = 0;
+                mSnappedScrolledY = currentScrollY - mMaxTranslation;
+            } else if (mTranslationY <= -mMaxTranslation) { // hide or stay hidden
+                mHeaderHidden = true;
+                mSnappedScrolledY = currentScrollY;
+            }
+        }
+    }
+
+    private void apply() {
+        int uncappedTranslationY = mTranslationY;
+        mTranslationY = Math.max(mTranslationY, -mMaxTranslation);
+        if (mTranslationY != uncappedTranslationY) {
+            // we hide it completely if already capped (for opening search anim)
+            mPredictionRow.setVisibility(View.INVISIBLE);
+        } else {
+            mPredictionRow.setVisibility(View.VISIBLE);
+            mPredictionRow.setTranslationY(uncappedTranslationY);
+        }
+        mTabLayout.setTranslationY(mTranslationY);
+        mDivider.setTranslationY(mTopOnlyMode ? uncappedTranslationY : mTranslationY);
+        mClip.top = mMaxTranslation + mTranslationY;
+        // clipping on a draw might cause additional redraw
+        mMainRV.setClipBounds(mClip);
+        if (mWorkRV != null) {
+            mWorkRV.setClipBounds(mClip);
+        }
+    }
+
+    private void setExpanded(boolean expand) {
+        int translateTo = expand ? 0 : -mMaxTranslation;
+        mAnimator.setIntValues(mTranslationY, translateTo);
+        mAnimator.addUpdateListener(this);
+        mAnimator.setDuration(150);
+        mAnimator.start();
+        mHeaderHidden = !expand;
+        mSnappedScrolledY = expand ? getCurrentScroll() - mMaxTranslation : getCurrentScroll();
+    }
+
+    public boolean isExpanded() {
+        return !mHeaderHidden;
+    }
+
+    private int getCurrentScroll() {
+        return mMainRVActive ? mMainScrolledY : mWorkScrolledY;
+    }
+
+    @Override
+    public void onAnimationUpdate(ValueAnimator animation) {
+        mTranslationY = (Integer) animation.getAnimatedValue();
+        apply();
+    }
+
+}
+
+