Create SearchBarMover

app/src/main/java/com/hippo/widget/SearchBarMover.java

@@ -0,0 +1,213 @@
+/*
+ * Copyright 2016 Hippo Seven
+ *
+ * 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.hippo.widget;
+
+import android.animation.Animator;
+import android.animation.ValueAnimator;
+import android.support.v7.widget.RecyclerView;
+import android.view.View;
+
+import com.hippo.yorozuya.MathUtils;
+import com.hippo.yorozuya.SimpleAnimatorListener;
+import com.hippo.yorozuya.ViewUtils;
+
+public class SearchBarMover extends RecyclerView.OnScrollListener {
+
+    private static final long ANIMATE_TIME = 300L;
+
+    private boolean mShow;
+    private ValueAnimator mSearchBarMoveAnimator;
+    private final Helper mHelper;
+    private final View mSearchBar;
+
+    public SearchBarMover(Helper helper, View searchBar, RecyclerView... recyclerViews) {
+        mHelper = helper;
+        mSearchBar = searchBar;
+        for (RecyclerView recyclerView: recyclerViews) {
+            recyclerView.addOnScrollListener(this);
+        }
+    }
+
+    public void cancelAnimation() {
+        if (mSearchBarMoveAnimator != null) {
+            mSearchBarMoveAnimator.cancel();
+        }
+    }
+
+    @Override
+    public void onScrollStateChanged(RecyclerView recyclerView, int newState){
+        if (newState == RecyclerView.SCROLL_STATE_IDLE && mHelper.isValidView(recyclerView)) {
+            returnSearchBarPosition();
+        }
+    }
+
+    @Override
+    public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
+        if (mHelper.isValidView(recyclerView)) {
+            int oldBottom = (int) ViewUtils.getY2(mSearchBar);
+            int offsetYStep = MathUtils.clamp(-dy, -oldBottom, -(int) mSearchBar.getTranslationY());
+            if (offsetYStep != 0) {
+                ViewUtils.translationYBy(mSearchBar, offsetYStep);
+            }
+        }
+    }
+
+    public void returnSearchBarPosition() {
+        returnSearchBarPosition(true);
+    }
+
+    @SuppressWarnings("SimplifiableIfStatement")
+    public void returnSearchBarPosition(boolean animation) {
+        if (mSearchBar.getHeight() == 0) {
+            // Layout not called
+            return;
+        }
+
+        boolean show;
+        if (mHelper.forceShowSearchBar()) {
+            show = true;
+        } else {
+            RecyclerView recyclerView = mHelper.getValidRecyclerView();
+            if (!recyclerView.isShown()) {
+                show = true;
+            } else if (recyclerView.computeVerticalScrollOffset() < mSearchBar.getBottom()){
+                show = true;
+            } else {
+                show = (int) ViewUtils.getY2(mSearchBar) > (mSearchBar.getHeight()) / 2;
+            }
+        }
+
+        int offset;
+        if (show) {
+            offset = -(int) mSearchBar.getTranslationY();
+        } else {
+            offset = -(int) ViewUtils.getY2(mSearchBar);
+        }
+
+        if (offset == 0) {
+            // No need to scroll
+            return;
+        }
+
+        if (animation) {
+            if (mSearchBarMoveAnimator != null) {
+                if (mShow == show) {
+                    // The same target, no need to do animation
+                    return;
+                } else {
+                    // Cancel it
+                    mSearchBarMoveAnimator.cancel();
+                    mSearchBarMoveAnimator = null;
+                }
+            }
+
+            mShow = show;
+            final ValueAnimator va = ValueAnimator.ofInt(0, offset);
+            va.setDuration(ANIMATE_TIME);
+            va.addListener(new SimpleAnimatorListener() {
+                @Override
+                public void onAnimationEnd(Animator animation) {
+                    mSearchBarMoveAnimator = null;
+                }
+            });
+            va.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
+                int lastValue;
+                @Override
+                public void onAnimationUpdate(ValueAnimator animation) {
+                    int value = (Integer) animation.getAnimatedValue();
+                    int offsetStep = value - lastValue;
+                    lastValue = value;
+                    ViewUtils.translationYBy(mSearchBar, offsetStep);
+                }
+            });
+            mSearchBarMoveAnimator = va;
+            va.start();
+        } else {
+            if (mSearchBarMoveAnimator != null) {
+                mSearchBarMoveAnimator.cancel();
+            }
+            ViewUtils.translationYBy(mSearchBar, offset);
+        }
+    }
+
+    public void showSearchBar() {
+        showSearchBar(true);
+    }
+
+    public void showSearchBar(boolean animation) {
+        if (mSearchBar.getHeight() == 0) {
+            // Layout not called
+            return;
+        }
+
+        final int offset = -(int) mSearchBar.getTranslationY();
+
+        if (offset == 0) {
+            // No need to scroll
+            return;
+        }
+
+        if (animation) {
+            if (mSearchBarMoveAnimator != null) {
+                if (mShow) {
+                    // The same target, no need to do animation
+                    return;
+                } else {
+                    // Cancel it
+                    mSearchBarMoveAnimator.cancel();
+                    mSearchBarMoveAnimator = null;
+                }
+            }
+
+            mShow = true;
+            final ValueAnimator va = ValueAnimator.ofInt(0, offset);
+            va.setDuration(ANIMATE_TIME);
+            va.addListener(new SimpleAnimatorListener() {
+                @Override
+                public void onAnimationEnd(Animator animation) {
+                    mSearchBarMoveAnimator = null;
+                }
+            });
+            va.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
+                int lastValue;
+                @Override
+                public void onAnimationUpdate(ValueAnimator animation) {
+                    int value = (Integer) animation.getAnimatedValue();
+                    int offsetStep = value - lastValue;
+                    lastValue = value;
+                    ViewUtils.translationYBy(mSearchBar, offsetStep);
+                }
+            });
+            mSearchBarMoveAnimator = va;
+            va.start();
+        } else {
+            if (mSearchBarMoveAnimator != null) {
+                mSearchBarMoveAnimator.cancel();
+            }
+            ViewUtils.translationYBy(mSearchBar, offset);
+        }
+    }
+
+    public interface Helper {
+
+        boolean isValidView(RecyclerView recyclerView);
+
+        RecyclerView getValidRecyclerView();
+
+        boolean forceShowSearchBar();
+    }
+}