Hack to disable overscroll effect of swipe to update

1 files changed, 473 insertions, 0 deletions

diff --git a/OpenKeychain/src/main/java/android/support/v4/widget/NoScrollableSwipeRefreshLayout.java b/OpenKeychain/src/main/java/android/support/v4/widget/NoScrollableSwipeRefreshLayout.java
new file mode 100644
index 000000000..9bbcfe698
--- /dev/null
+++ b/OpenKeychain/src/main/java/android/support/v4/widget/NoScrollableSwipeRefreshLayout.java
@@ -0,0 +1,473 @@
+/*
+ * Copyright (C) 2013 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 android.support.v4.widget;
+
+import android.content.Context;
+import android.content.res.Resources;
+import android.content.res.TypedArray;
+import android.graphics.Canvas;
+import android.support.v4.view.ViewCompat;
+import android.util.AttributeSet;
+import android.util.DisplayMetrics;
+import android.view.MotionEvent;
+import android.view.View;
+import android.view.ViewConfiguration;
+import android.view.ViewGroup;
+import android.view.animation.AccelerateInterpolator;
+import android.view.animation.Animation;
+import android.view.animation.Animation.AnimationListener;
+import android.view.animation.DecelerateInterpolator;
+import android.view.animation.Transformation;
+import android.widget.AbsListView;
+
+
+/**
+ * Same as SwipeRefreshLayout, only updateContentOffsetTop and REFRESH_TRIGGER_DISTANCE
+ * have been modified!
+ */
+public class NoScrollableSwipeRefreshLayout extends ViewGroup {
+    private static final long RETURN_TO_ORIGINAL_POSITION_TIMEOUT = 300;
+    private static final float ACCELERATE_INTERPOLATION_FACTOR = 1.5f;
+    private static final float DECELERATE_INTERPOLATION_FACTOR = 2f;
+    private static final float PROGRESS_BAR_HEIGHT = 4;
+    private static final float MAX_SWIPE_DISTANCE_FACTOR = .6f;
+    private static final int REFRESH_TRIGGER_DISTANCE = 200;
+
+    private SwipeProgressBar mProgressBar; //the thing that shows progress is going
+    private View mTarget; //the content that gets pulled down
+    private int mOriginalOffsetTop;
+    private OnRefreshListener mListener;
+    private MotionEvent mDownEvent;
+    private int mFrom;
+    private boolean mRefreshing = false;
+    private int mTouchSlop;
+    private float mDistanceToTriggerSync = -1;
+    private float mPrevY;
+    private int mMediumAnimationDuration;
+    private float mFromPercentage = 0;
+    private float mCurrPercentage = 0;
+    private int mProgressBarHeight;
+    private int mCurrentTargetOffsetTop;
+    // Target is returning to its start offset because it was cancelled or a
+    // refresh was triggered.
+    private boolean mReturningToStart;
+    private final DecelerateInterpolator mDecelerateInterpolator;
+    private final AccelerateInterpolator mAccelerateInterpolator;
+    private static final int[] LAYOUT_ATTRS = new int[] {
+            android.R.attr.enabled
+    };
+
+    private final Animation mAnimateToStartPosition = new Animation() {
+        @Override
+        public void applyTransformation(float interpolatedTime, Transformation t) {
+            int targetTop = 0;
+            if (mFrom != mOriginalOffsetTop) {
+                targetTop = (mFrom + (int)((mOriginalOffsetTop - mFrom) * interpolatedTime));
+            }
+            int offset = targetTop - mTarget.getTop();
+            final int currentTop = mTarget.getTop();
+            if (offset + currentTop < 0) {
+                offset = 0 - currentTop;
+            }
+            setTargetOffsetTopAndBottom(offset);
+        }
+    };
+
+    private Animation mShrinkTrigger = new Animation() {
+        @Override
+        public void applyTransformation(float interpolatedTime, Transformation t) {
+            float percent = mFromPercentage + ((0 - mFromPercentage) * interpolatedTime);
+            mProgressBar.setTriggerPercentage(percent);
+        }
+    };
+
+    private final AnimationListener mReturnToStartPositionListener = new BaseAnimationListener() {
+        @Override
+        public void onAnimationEnd(Animation animation) {
+            // Once the target content has returned to its start position, reset
+            // the target offset to 0
+            mCurrentTargetOffsetTop = 0;
+        }
+    };
+
+    private final AnimationListener mShrinkAnimationListener = new BaseAnimationListener() {
+        @Override
+        public void onAnimationEnd(Animation animation) {
+            mCurrPercentage = 0;
+        }
+    };
+
+    private final Runnable mReturnToStartPosition = new Runnable() {
+
+        @Override
+        public void run() {
+            mReturningToStart = true;
+            animateOffsetToStartPosition(mCurrentTargetOffsetTop + getPaddingTop(),
+                    mReturnToStartPositionListener);
+        }
+
+    };
+
+    // Cancel the refresh gesture and animate everything back to its original state.
+    private final Runnable mCancel = new Runnable() {
+
+        @Override
+        public void run() {
+            mReturningToStart = true;
+            // Timeout fired since the user last moved their finger; animate the
+            // trigger to 0 and put the target back at its original position
+            if (mProgressBar != null) {
+                mFromPercentage = mCurrPercentage;
+                mShrinkTrigger.setDuration(mMediumAnimationDuration);
+                mShrinkTrigger.setAnimationListener(mShrinkAnimationListener);
+                mShrinkTrigger.reset();
+                mShrinkTrigger.setInterpolator(mDecelerateInterpolator);
+                startAnimation(mShrinkTrigger);
+            }
+            animateOffsetToStartPosition(mCurrentTargetOffsetTop + getPaddingTop(),
+                    mReturnToStartPositionListener);
+        }
+
+    };
+
+    /**
+     * Simple constructor to use when creating a SwipeRefreshLayout from code.
+     * @param context
+     */
+    public NoScrollableSwipeRefreshLayout(Context context) {
+        this(context, null);
+    }
+
+    /**
+     * Constructor that is called when inflating SwipeRefreshLayout from XML.
+     * @param context
+     * @param attrs
+     */
+    public NoScrollableSwipeRefreshLayout(Context context, AttributeSet attrs) {
+        super(context, attrs);
+
+        mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
+
+        mMediumAnimationDuration = getResources().getInteger(
+                android.R.integer.config_mediumAnimTime);
+
+        setWillNotDraw(false);
+        mProgressBar = new SwipeProgressBar(this);
+        final DisplayMetrics metrics = getResources().getDisplayMetrics();
+        mProgressBarHeight = (int) (metrics.density * PROGRESS_BAR_HEIGHT);
+        mDecelerateInterpolator = new DecelerateInterpolator(DECELERATE_INTERPOLATION_FACTOR);
+        mAccelerateInterpolator = new AccelerateInterpolator(ACCELERATE_INTERPOLATION_FACTOR);
+
+        final TypedArray a = context.obtainStyledAttributes(attrs, LAYOUT_ATTRS);
+        setEnabled(a.getBoolean(0, true));
+        a.recycle();
+    }
+
+    @Override
+    public void onAttachedToWindow() {
+        super.onAttachedToWindow();
+        removeCallbacks(mCancel);
+        removeCallbacks(mReturnToStartPosition);
+    }
+
+    @Override
+    public void onDetachedFromWindow() {
+        super.onDetachedFromWindow();
+        removeCallbacks(mReturnToStartPosition);
+        removeCallbacks(mCancel);
+    }
+
+    private void animateOffsetToStartPosition(int from, AnimationListener listener) {
+        mFrom = from;
+        mAnimateToStartPosition.reset();
+        mAnimateToStartPosition.setDuration(mMediumAnimationDuration);
+        mAnimateToStartPosition.setAnimationListener(listener);
+        mAnimateToStartPosition.setInterpolator(mDecelerateInterpolator);
+        mTarget.startAnimation(mAnimateToStartPosition);
+    }
+
+    /**
+     * Set the listener to be notified when a refresh is triggered via the swipe
+     * gesture.
+     */
+    public void setOnRefreshListener(OnRefreshListener listener) {
+        mListener = listener;
+    }
+
+    private void setTriggerPercentage(float percent) {
+        if (percent == 0f) {
+            // No-op. A null trigger means it's uninitialized, and setting it to zero-percent
+            // means we're trying to reset state, so there's nothing to reset in this case.
+            mCurrPercentage = 0;
+            return;
+        }
+        mCurrPercentage = percent;
+        mProgressBar.setTriggerPercentage(percent);
+    }
+
+    /**
+     * Notify the widget that refresh state has changed. Do not call this when
+     * refresh is triggered by a swipe gesture.
+     *
+     * @param refreshing Whether or not the view should show refresh progress.
+     */
+    public void setRefreshing(boolean refreshing) {
+        if (mRefreshing != refreshing) {
+            ensureTarget();
+            mCurrPercentage = 0;
+            mRefreshing = refreshing;
+            if (mRefreshing) {
+                mProgressBar.start();
+            } else {
+                mProgressBar.stop();
+            }
+        }
+    }
+
+    /**
+     * Set the four colors used in the progress animation. The first color will
+     * also be the color of the bar that grows in response to a user swipe
+     * gesture.
+     *
+     * @param colorRes1 Color resource.
+     * @param colorRes2 Color resource.
+     * @param colorRes3 Color resource.
+     * @param colorRes4 Color resource.
+     */
+    public void setColorScheme(int colorRes1, int colorRes2, int colorRes3, int colorRes4) {
+        ensureTarget();
+        final Resources res = getResources();
+        final int color1 = res.getColor(colorRes1);
+        final int color2 = res.getColor(colorRes2);
+        final int color3 = res.getColor(colorRes3);
+        final int color4 = res.getColor(colorRes4);
+        mProgressBar.setColorScheme(color1, color2, color3,color4);
+    }
+
+    /**
+     * @return Whether the SwipeRefreshWidget is actively showing refresh
+     *         progress.
+     */
+    public boolean isRefreshing() {
+        return mRefreshing;
+    }
+
+    private void ensureTarget() {
+        // Don't bother getting the parent height if the parent hasn't been laid out yet.
+        if (mTarget == null) {
+            if (getChildCount() > 1 && !isInEditMode()) {
+                throw new IllegalStateException(
+                        "SwipeRefreshLayout can host only one direct child");
+            }
+            mTarget = getChildAt(0);
+            mOriginalOffsetTop = mTarget.getTop() + getPaddingTop();
+        }
+        if (mDistanceToTriggerSync == -1) {
+            if (getParent() != null && ((View)getParent()).getHeight() > 0) {
+                final DisplayMetrics metrics = getResources().getDisplayMetrics();
+                mDistanceToTriggerSync = (int) Math.min(
+                        ((View) getParent()) .getHeight() * MAX_SWIPE_DISTANCE_FACTOR,
+                        REFRESH_TRIGGER_DISTANCE * metrics.density);
+            }
+        }
+    }
+
+    @Override
+    public void draw(Canvas canvas) {
+        super.draw(canvas);
+        mProgressBar.draw(canvas);
+    }
+
+    @Override
+    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
+        final int width =  getMeasuredWidth();
+        final int height = getMeasuredHeight();
+        mProgressBar.setBounds(0, 0, width, mProgressBarHeight);
+        if (getChildCount() == 0) {
+            return;
+        }
+        final View child = getChildAt(0);
+        final int childLeft = getPaddingLeft();
+        final int childTop = mCurrentTargetOffsetTop + getPaddingTop();
+        final int childWidth = width - getPaddingLeft() - getPaddingRight();
+        final int childHeight = height - getPaddingTop() - getPaddingBottom();
+        child.layout(childLeft, childTop, childLeft + childWidth, childTop + childHeight);
+    }
+
+    @Override
+    public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
+        if (getChildCount() > 1 && !isInEditMode()) {
+            throw new IllegalStateException("SwipeRefreshLayout can host only one direct child");
+        }
+        if (getChildCount() > 0) {
+            getChildAt(0).measure(
+                    MeasureSpec.makeMeasureSpec(
+                            getMeasuredWidth() - getPaddingLeft() - getPaddingRight(),
+                            MeasureSpec.EXACTLY),
+                    MeasureSpec.makeMeasureSpec(
+                            getMeasuredHeight() - getPaddingTop() - getPaddingBottom(),
+                            MeasureSpec.EXACTLY));
+        }
+    }
+
+    /**
+     * @return Whether it is possible for the child view of this layout to
+     *         scroll up. Override this if the child view is a custom view.
+     */
+    public boolean canChildScrollUp() {
+        if (android.os.Build.VERSION.SDK_INT < 14) {
+            if (mTarget instanceof AbsListView) {
+                final AbsListView absListView = (AbsListView) mTarget;
+                return absListView.getChildCount() > 0
+                        && (absListView.getFirstVisiblePosition() > 0 || absListView.getChildAt(0)
+                        .getTop() < absListView.getPaddingTop());
+            } else {
+                return mTarget.getScrollY() > 0;
+            }
+        } else {
+            return ViewCompat.canScrollVertically(mTarget, -1);
+        }
+    }
+
+    @Override
+    public boolean onInterceptTouchEvent(MotionEvent ev) {
+        ensureTarget();
+        boolean handled = false;
+        if (mReturningToStart && ev.getAction() == MotionEvent.ACTION_DOWN) {
+            mReturningToStart = false;
+        }
+        if (isEnabled() && !mReturningToStart && !canChildScrollUp()) {
+            handled = onTouchEvent(ev);
+        }
+        return !handled ? super.onInterceptTouchEvent(ev) : handled;
+    }
+
+    @Override
+    public void requestDisallowInterceptTouchEvent(boolean b) {
+        // Nope.
+    }
+
+    @Override
+    public boolean onTouchEvent(MotionEvent event) {
+        final int action = event.getAction();
+        boolean handled = false;
+        switch (action) {
+            case MotionEvent.ACTION_DOWN:
+                mCurrPercentage = 0;
+                mDownEvent = MotionEvent.obtain(event);
+                mPrevY = mDownEvent.getY();
+                break;
+            case MotionEvent.ACTION_MOVE:
+                if (mDownEvent != null && !mReturningToStart) {
+                    final float eventY = event.getY();
+                    float yDiff = eventY - mDownEvent.getY();
+                    if (yDiff > mTouchSlop) {
+                        // User velocity passed min velocity; trigger a refresh
+                        if (yDiff > mDistanceToTriggerSync) {
+                            // User movement passed distance; trigger a refresh
+                            startRefresh();
+                            handled = true;
+                            break;
+                        } else {
+                            // Just track the user's movement
+                            setTriggerPercentage(
+                                    mAccelerateInterpolator.getInterpolation(
+                                            yDiff / mDistanceToTriggerSync));
+                            float offsetTop = yDiff;
+                            if (mPrevY > eventY) {
+                                offsetTop = yDiff - mTouchSlop;
+                            }
+                            updateContentOffsetTop((int) (offsetTop));
+                            if (mPrevY > eventY && (mTarget.getTop() < mTouchSlop)) {
+                                // If the user puts the view back at the top, we
+                                // don't need to. This shouldn't be considered
+                                // cancelling the gesture as the user can restart from the top.
+                                removeCallbacks(mCancel);
+                            } else {
+                                updatePositionTimeout();
+                            }
+                            mPrevY = event.getY();
+                            handled = true;
+                        }
+                    }
+                }
+                break;
+            case MotionEvent.ACTION_UP:
+            case MotionEvent.ACTION_CANCEL:
+                if (mDownEvent != null) {
+                    mDownEvent.recycle();
+                    mDownEvent = null;
+                }
+                break;
+        }
+        return handled;
+    }
+
+    private void startRefresh() {
+        removeCallbacks(mCancel);
+        mReturnToStartPosition.run();
+        setRefreshing(true);
+        mListener.onRefresh();
+    }
+
+    private void updateContentOffsetTop(int targetTop) {
+        final int currentTop = mTarget.getTop();
+        if (targetTop > mDistanceToTriggerSync) {
+            targetTop = (int) mDistanceToTriggerSync;
+        } else if (targetTop < 0) {
+            targetTop = 0;
+        }
+//        setTargetOffsetTopAndBottom(targetTop - currentTop);
+    }
+
+    private void setTargetOffsetTopAndBottom(int offset) {
+        mTarget.offsetTopAndBottom(offset);
+        mCurrentTargetOffsetTop = mTarget.getTop();
+    }
+
+    private void updatePositionTimeout() {
+        removeCallbacks(mCancel);
+        postDelayed(mCancel, RETURN_TO_ORIGINAL_POSITION_TIMEOUT);
+    }
+
+    /**
+     * Classes that wish to be notified when the swipe gesture correctly
+     * triggers a refresh should implement this interface.
+     */
+    public interface OnRefreshListener {
+        public void onRefresh();
+    }
+
+    /**
+     * Simple AnimationListener to avoid having to implement unneeded methods in
+     * AnimationListeners.
+     */
+    private class BaseAnimationListener implements AnimationListener {
+        @Override
+        public void onAnimationStart(Animation animation) {
+        }
+
+        @Override
+        public void onAnimationEnd(Animation animation) {
+        }
+
+        @Override
+        public void onAnimationRepeat(Animation animation) {
+        }
+    }
+}
\ No newline at end of file