Java tutorial
/* * Copyright (C) 2014 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.hakerjack.experiments; import android.content.Context; import android.content.res.TypedArray; import android.support.v4.view.MotionEventCompat; import android.support.v4.view.ViewCompat; import android.util.AttributeSet; import android.util.DisplayMetrics; import android.util.Log; import android.view.MotionEvent; import android.view.View; import android.view.ViewConfiguration; import android.view.ViewGroup; 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; /** * This is a modified version of Android's {@link android.support.v4.widget.SwipeRefreshLayout}. * It uses our own spinner indicator instead of the android default one. It also support customized * indicator as you can subclass {@link SwipeRefreshLayoutIndicator} and use your own custom class for * drawing and loading animation. * * Created by kjia on 9/29/15. */ public class CustomSwipeRefreshLayout extends ViewGroup { private static final String LOG_TAG = CustomSwipeRefreshLayout.class.getSimpleName(); private static final int MAX_ALPHA = 255; private static final int STARTING_PROGRESS_ALPHA = (int) (.1f * MAX_ALPHA); /** * The diameter (size) of the spinner */ private static final int SPINNER_DIAMETER = 30; /** * Distance on y until which we don't show the spinner */ private static final int HIDE_SPINNER_DISTANCE = 30; private static final float DECELERATE_INTERPOLATION_FACTOR = 2f; private static final int INVALID_POINTER = -1; private static final float DRAG_RATE = .5f; private static final int SCALE_DOWN_DURATION = 150; private static final int ALPHA_ANIMATION_DURATION = 300; private static final int ANIMATE_TO_TRIGGER_DURATION = 200; private static final int ANIMATE_TO_START_DURATION = 200; /** * Default offset in dips from the top of the view to where the progress spinner should stop */ private static final int DEFAULT_SPINNER_TARGET = 80; private View mTarget; // the target of the gesture private OnRefreshListener mListener; private boolean mRefreshing = false; private int mTouchSlop; private float mTotalDragDistance = -1; private int mMediumAnimationDuration; private int mCurrentTargetOffsetTop; // Whether or not the starting offset has been determined. private boolean mOriginalOffsetCalculated = false; private float mInitialMotionY; private float mInitialDownY; private boolean mIsBeingDragged; private int mActivePointerId = INVALID_POINTER; // Whether this item is scaled up rather than clipped private boolean mScale; // Target is returning to its start offset because it was cancelled or a // refresh was triggered. private boolean mReturningToStart; private final DecelerateInterpolator mDecelerateInterpolator; private static final int[] LAYOUT_ATTRS = new int[] { android.R.attr.enabled }; private SwipeRefreshLayoutIndicator mSpinner; private int mCircleViewIndex = -1; protected int mFrom; private float mStartingScale; protected int mOriginalOffsetTop; private OffsetViewListener mViewListener; private Animation mScaleAnimation; private Animation mScaleDownAnimation; private Animation mScaleDownToStartAnimation; private float mSpinnerFinalOffset; private boolean mNotify; private int mSpinnerWidth; private int mSpinnerHeight; private float mHideSpinnerDistance; // Whether the client has set a custom starting position; private boolean mUsingCustomStart; private Animation.AnimationListener mRefreshListener = new Animation.AnimationListener() { @Override public void onAnimationStart(Animation animation) { } @Override public void onAnimationRepeat(Animation animation) { } @Override public void onAnimationEnd(Animation animation) { if (mRefreshing) { // Make sure the progress view is fully visible mSpinner.setSpinnerAlpha(MAX_ALPHA); mSpinner.startLoadingAnimation(); if (mNotify) { if (mListener != null) { mListener.onRefresh(); } } } else { mSpinner.stopLoadingAnimation(); mSpinner.setVisibility(View.GONE); } mCurrentTargetOffsetTop = mSpinner.getTop(); } }; /** * Simple constructor to use when creating a DoublePlaySwipeRefreshLayout from code. * * @param context */ public CustomSwipeRefreshLayout(Context context) { this(context, null); } /** * Constructor that is called when inflating DoublePlaySwipeRefreshLayout from XML. * * @param context * @param attrs */ public CustomSwipeRefreshLayout(Context context, AttributeSet attrs) { super(context, attrs); mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop(); mMediumAnimationDuration = getResources().getInteger(android.R.integer.config_mediumAnimTime); setWillNotDraw(false); mDecelerateInterpolator = new DecelerateInterpolator(DECELERATE_INTERPOLATION_FACTOR); final TypedArray a = context.obtainStyledAttributes(attrs, LAYOUT_ATTRS); setEnabled(a.getBoolean(0, true)); a.recycle(); final DisplayMetrics metrics = getResources().getDisplayMetrics(); mSpinnerWidth = (int) (SPINNER_DIAMETER * metrics.density); mSpinnerHeight = (int) (SPINNER_DIAMETER * metrics.density); createProgressView(); ViewCompat.setChildrenDrawingOrderEnabled(this, true); // the absolute offset has to take into account that the circle starts at an offset mSpinnerFinalOffset = DEFAULT_SPINNER_TARGET * metrics.density; mTotalDragDistance = mSpinnerFinalOffset; mHideSpinnerDistance = HIDE_SPINNER_DISTANCE * metrics.density; } /** * The refresh indicator starting and resting position is always positioned * near the top of the refreshing content. This position is a consistent * location, but can be adjusted in either direction based on whether or not * there is a toolbar or actionbar present. * * @param scale Set to true if there is no view at a higher z-order than * where the progress spinner is set to appear. * @param start The offset in pixels from the top of this view at which the * progress spinner should appear. * @param end The offset in pixels from the top of this view at which the * progress spinner should come to rest after a successful swipe * gesture. */ public void setProgressViewOffset(boolean scale, int start, int end) { mScale = scale; mSpinner.setVisibility(View.GONE); mOriginalOffsetTop = mCurrentTargetOffsetTop = start; if (end >= 0) { mSpinnerFinalOffset = end; } mUsingCustomStart = true; mSpinner.invalidate(); } /** * The refresh indicator resting position is always positioned near the top * of the refreshing content. This position is a consistent location, but * can be adjusted in either direction based on whether or not there is a * toolbar or actionbar present. * * @param scale Set to true if there is no view at a higher z-order than * where the progress spinner is set to appear. * @param end The offset in pixels from the top of this view at which the * progress spinner should come to rest after a successful swipe * gesture. */ public void setProgressViewEndTarget(boolean scale, int end) { mSpinnerFinalOffset = end; mScale = scale; mSpinner.invalidate(); } protected int getChildDrawingOrder(int childCount, int i) { if (mCircleViewIndex < 0) { return i; } else if (i == childCount - 1) { // Draw the selected child last return mCircleViewIndex; } else if (i >= mCircleViewIndex) { // Move the children after the selected child earlier one return i + 1; } else { // Keep the children before the selected child the same return i; } } private void createProgressView() { mSpinner = new SwipeRefreshLayoutIndicator(getContext(), this); mSpinner.setVisibility(View.GONE); addView(mSpinner); } /** * Set the listener to be notified when a refresh is triggered via the swipe * gesture. */ public void setOnRefreshListener(OnRefreshListener listener) { mListener = listener; } /** * Pre API 11, alpha is used to make the progress circle appear instead of scale. */ private boolean isAlphaUsedForScale() { return android.os.Build.VERSION.SDK_INT < 11; } /** * 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 (refreshing && mRefreshing != refreshing) { // scale and show mRefreshing = refreshing; mNotify = false; } else { setRefreshing(refreshing, false /* notify */); } } private void startScaleUpAnimation(AnimationListener listener) { mSpinner.setVisibility(View.VISIBLE); if (android.os.Build.VERSION.SDK_INT >= 11) { // Pre API 11, alpha is used in place of scale up to show the // progress circle appearing. // Don't adjust the alpha during appearance otherwise. mSpinner.setSpinnerAlpha(MAX_ALPHA); } mScaleAnimation = new Animation() { @Override public void applyTransformation(float interpolatedTime, Transformation t) { setAnimationProgress(interpolatedTime); } }; mScaleAnimation.setDuration(mMediumAnimationDuration); if (listener != null) { mSpinner.setAnimationListener(listener); } mSpinner.clearAnimation(); mSpinner.startAnimation(mScaleAnimation); } /** * Pre API 11, this does an alpha animation. * @param progress */ private void setAnimationProgress(float progress) { if (isAlphaUsedForScale()) { mSpinner.setSpinnerAlpha((int) (progress * MAX_ALPHA)); } else { ViewCompat.setScaleX(mSpinner, progress); ViewCompat.setScaleY(mSpinner, progress); } } private void setRefreshing(boolean refreshing, final boolean notify) { if (mRefreshing != refreshing) { mNotify = notify; ensureTarget(); mRefreshing = refreshing; if (mRefreshing) { animateOffsetToCorrectPosition(mCurrentTargetOffsetTop, mRefreshListener); } else { animateOffsetToStartPosition(mCurrentTargetOffsetTop, mRefreshListener); } } } private void startScaleDownAnimation(Animation.AnimationListener listener) { mScaleDownAnimation = new Animation() { @Override public void applyTransformation(float interpolatedTime, Transformation t) { setAnimationProgress(1 - interpolatedTime); } }; mScaleDownAnimation.setDuration(SCALE_DOWN_DURATION); mSpinner.setAnimationListener(listener); mSpinner.clearAnimation(); mSpinner.startAnimation(mScaleDownAnimation); } /** * Set the background color of the progress spinner disc. * * @param colorRes Resource id of the color. */ public void setProgressBackgroundColorSchemeResource(int colorRes) { setProgressBackgroundColorSchemeColor(getResources().getColor(colorRes)); } /** * Set the background color of the progress spinner disc. * * @param color */ public void setProgressBackgroundColorSchemeColor(int color) { mSpinner.setBackgroundColor(color); } /** * @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) { for (int i = 0; i < getChildCount(); i++) { View child = getChildAt(i); if (!child.equals(mSpinner)) { mTarget = child; break; } } } } /** * Set the distance to trigger a sync in dips * * @param distance */ public void setDistanceToTriggerSync(int distance) { mTotalDragDistance = distance; } @Override protected void onLayout(boolean changed, int left, int top, int right, int bottom) { final int width = getMeasuredWidth(); final int height = getMeasuredHeight(); if (getChildCount() == 0) { return; } if (mTarget == null) { ensureTarget(); } if (mTarget == null) { return; } final View child = mTarget; final int childLeft = getPaddingLeft(); final int childTop = getPaddingTop(); final int childWidth = width - getPaddingLeft() - getPaddingRight(); final int childHeight = height - getPaddingTop() - getPaddingBottom(); child.layout(childLeft, childTop, childLeft + childWidth, childTop + childHeight); int circleWidth = mSpinner.getMeasuredWidth(); int circleHeight = mSpinner.getMeasuredHeight(); mSpinner.layout((width / 2 - circleWidth / 2), mCurrentTargetOffsetTop, (width / 2 + circleWidth / 2), mCurrentTargetOffsetTop + circleHeight); } @Override public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { super.onMeasure(widthMeasureSpec, heightMeasureSpec); if (mTarget == null) { ensureTarget(); } if (mTarget == null) { return; } mTarget.measure( MeasureSpec.makeMeasureSpec(getMeasuredWidth() - getPaddingLeft() - getPaddingRight(), MeasureSpec.EXACTLY), MeasureSpec.makeMeasureSpec(getMeasuredHeight() - getPaddingTop() - getPaddingBottom(), MeasureSpec.EXACTLY)); mSpinner.measure(MeasureSpec.makeMeasureSpec(mSpinnerWidth, MeasureSpec.EXACTLY), MeasureSpec.makeMeasureSpec(mSpinnerHeight, MeasureSpec.EXACTLY)); if (!mUsingCustomStart && !mOriginalOffsetCalculated) { mOriginalOffsetCalculated = true; mCurrentTargetOffsetTop = mOriginalOffsetTop = -mSpinner.getMeasuredHeight(); } mCircleViewIndex = -1; // Get the index of the circleview. for (int index = 0; index < getChildCount(); index++) { if (getChildAt(index) == mSpinner) { mCircleViewIndex = index; break; } } } /** * Get the diameter of the progress circle that is displayed as part of the * swipe to refresh layout. This is not valid until a measure pass has * completed. * * @return Diameter in pixels of the progress circle view. */ public int getProgressCircleDiameter() { return mSpinner != null ? mSpinner.getMeasuredHeight() : 0; } /** * @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 ViewCompat.canScrollVertically(mTarget, -1) || mTarget.getScrollY() > 0; } } else { return ViewCompat.canScrollVertically(mTarget, -1); } } @Override public boolean onInterceptTouchEvent(MotionEvent ev) { ensureTarget(); final int action = MotionEventCompat.getActionMasked(ev); if (mReturningToStart && action == MotionEvent.ACTION_DOWN) { mReturningToStart = false; } if (!isEnabled() || mReturningToStart || canChildScrollUp() || mRefreshing) { // Fail fast if we're not in a state where a swipe is possible return false; } switch (action) { case MotionEvent.ACTION_DOWN: int offset = mOriginalOffsetTop - mSpinner.getTop(); setTargetOffsetTopAndBottom(offset, true); mActivePointerId = MotionEventCompat.getPointerId(ev, 0); mIsBeingDragged = false; final float initialDownY = getMotionEventY(ev, mActivePointerId); if (initialDownY == -1) { return false; } mInitialDownY = initialDownY; break; case MotionEvent.ACTION_MOVE: if (mActivePointerId == INVALID_POINTER) { Log.e(LOG_TAG, "Got ACTION_MOVE event but don't have an active pointer id."); return false; } final float y = getMotionEventY(ev, mActivePointerId); if (y == -1) { return false; } final float yDiff = y - mInitialDownY; if (yDiff > mTouchSlop && !mIsBeingDragged) { mInitialMotionY = mInitialDownY + mTouchSlop; mIsBeingDragged = true; mSpinner.setSpinnerAlpha(STARTING_PROGRESS_ALPHA); } break; case MotionEventCompat.ACTION_POINTER_UP: onSecondaryPointerUp(ev); break; case MotionEvent.ACTION_UP: case MotionEvent.ACTION_CANCEL: mIsBeingDragged = false; mActivePointerId = INVALID_POINTER; break; } return mIsBeingDragged; } private float getMotionEventY(MotionEvent ev, int activePointerId) { final int index = MotionEventCompat.findPointerIndex(ev, activePointerId); if (index < 0) { return -1; } return MotionEventCompat.getY(ev, index); } @Override public void requestDisallowInterceptTouchEvent(boolean b) { // Nope. } private boolean isAnimationRunning(Animation animation) { return animation != null && animation.hasStarted() && !animation.hasEnded(); } @Override public boolean onTouchEvent(MotionEvent ev) { final int action = MotionEventCompat.getActionMasked(ev); if (mReturningToStart && action == MotionEvent.ACTION_DOWN) { mReturningToStart = false; } if (!isEnabled() || mReturningToStart || canChildScrollUp()) { // Fail fast if we're not in a state where a swipe is possible return false; } switch (action) { case MotionEvent.ACTION_DOWN: mActivePointerId = MotionEventCompat.getPointerId(ev, 0); mIsBeingDragged = false; break; case MotionEvent.ACTION_MOVE: { final int pointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId); if (pointerIndex < 0) { Log.e(LOG_TAG, "Got ACTION_MOVE event but have an invalid active pointer id."); return false; } final float y = MotionEventCompat.getY(ev, pointerIndex); final float overscrollTop = (y - mInitialMotionY) * DRAG_RATE; if (mIsBeingDragged) { float originalDragPercent = overscrollTop / mTotalDragDistance; if (originalDragPercent < 0) { return false; } float dragPercent = Math.min(1f, Math.abs(originalDragPercent)); float extraOS = Math.abs(overscrollTop) - mTotalDragDistance; float slingshotDist = mUsingCustomStart ? mSpinnerFinalOffset - mOriginalOffsetTop : mSpinnerFinalOffset; float tensionSlingshotPercent = Math.max(0, Math.min(extraOS, slingshotDist * 2) / slingshotDist); float tensionPercent = (float) ((tensionSlingshotPercent / 4) - Math.pow((tensionSlingshotPercent / 4), 2)) * 2f; float extraMove = (slingshotDist) * tensionPercent * 2; int targetY = mOriginalOffsetTop + (int) ((slingshotDist * dragPercent) + extraMove); // where 1.0f is a full circle if (mSpinner.getVisibility() != View.VISIBLE) { mSpinner.setVisibility(View.VISIBLE); } if (!mScale) { ViewCompat.setScaleX(mSpinner, 1f); ViewCompat.setScaleY(mSpinner, 1f); } // Animate spinner's alpha based on y position relative to max distance if (overscrollTop < mTotalDragDistance) { if (mScale) { setAnimationProgress(overscrollTop / mTotalDragDistance); } float overScrollTopToShow = overscrollTop - mHideSpinnerDistance; float progress; if (overScrollTopToShow > 0) { progress = overScrollTopToShow / (mTotalDragDistance - mHideSpinnerDistance); } else { progress = 0; } mSpinner.setSpinnerAlpha((int) (progress * MAX_ALPHA)); mSpinner.animateUnderDraggableDistance(dragPercent, tensionPercent); } mSpinner.animateUnderDrag(dragPercent, tensionPercent); int offset = targetY - mCurrentTargetOffsetTop; setTargetOffsetTopAndBottom(offset, true /* requires update */); } break; } case MotionEventCompat.ACTION_POINTER_DOWN: { final int index = MotionEventCompat.getActionIndex(ev); mActivePointerId = MotionEventCompat.getPointerId(ev, index); break; } case MotionEventCompat.ACTION_POINTER_UP: onSecondaryPointerUp(ev); break; case MotionEvent.ACTION_UP: case MotionEvent.ACTION_CANCEL: { if (mActivePointerId == INVALID_POINTER) { if (action == MotionEvent.ACTION_UP) { Log.e(LOG_TAG, "Got ACTION_UP event but don't have an active pointer id."); } return false; } final int pointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId); final float y = MotionEventCompat.getY(ev, pointerIndex); final float overscrollTop = (y - mInitialMotionY) * DRAG_RATE; mIsBeingDragged = false; if (overscrollTop > mTotalDragDistance) { setRefreshing(true, true /* notify */); } else { // cancel refresh mRefreshing = false; mSpinner.animateUnderDrag(0f, 0f); Animation.AnimationListener listener = null; if (!mScale) { listener = new Animation.AnimationListener() { @Override public void onAnimationStart(Animation animation) { } @Override public void onAnimationEnd(Animation animation) { if (!mScale) { startScaleDownAnimation(null); } } @Override public void onAnimationRepeat(Animation animation) { } }; } animateOffsetToStartPosition(mCurrentTargetOffsetTop, listener); } mActivePointerId = INVALID_POINTER; return false; } } return true; } private void animateOffsetToCorrectPosition(int from, AnimationListener listener) { mFrom = from; mAnimateToCorrectPosition.reset(); mAnimateToCorrectPosition.setDuration(ANIMATE_TO_TRIGGER_DURATION); mAnimateToCorrectPosition.setInterpolator(mDecelerateInterpolator); if (listener != null) { mSpinner.setAnimationListener(listener); } mSpinner.clearAnimation(); mSpinner.startAnimation(mAnimateToCorrectPosition); } private void animateOffsetToStartPosition(int from, AnimationListener listener) { if (mScale) { // Scale the item back down startScaleDownReturnToStartAnimation(from, listener); } else { mFrom = from; mAnimateToStartPosition.reset(); mAnimateToStartPosition.setDuration(ANIMATE_TO_START_DURATION); mAnimateToStartPosition.setInterpolator(mDecelerateInterpolator); if (listener != null) { mSpinner.setAnimationListener(listener); } mSpinner.clearAnimation(); mSpinner.startAnimation(mAnimateToStartPosition); } } private final Animation mAnimateToCorrectPosition = new Animation() { @Override public void applyTransformation(float interpolatedTime, Transformation t) { int targetTop = 0; int endTarget = 0; if (!mUsingCustomStart) { endTarget = (int) (mSpinnerFinalOffset - Math.abs(mOriginalOffsetTop)); } else { endTarget = (int) mSpinnerFinalOffset; } endTarget = (int) mSpinnerFinalOffset; targetTop = (mFrom + (int) ((endTarget - mFrom) * interpolatedTime)); int offset = targetTop - mCurrentTargetOffsetTop; setTargetOffsetTopAndBottom(offset, false /* requires update */); } }; private void moveToStart(float interpolatedTime) { int targetTop = 0; targetTop = (mFrom + (int) ((mOriginalOffsetTop - mFrom) * interpolatedTime)); int offset = targetTop - mSpinner.getTop(); setTargetOffsetTopAndBottom(offset, false /* requires update */); } private final Animation mAnimateToStartPosition = new Animation() { @Override public void applyTransformation(float interpolatedTime, Transformation t) { moveToStart(interpolatedTime); } }; private void startScaleDownReturnToStartAnimation(int from, Animation.AnimationListener listener) { mFrom = from; mStartingScale = ViewCompat.getScaleX(mSpinner); mScaleDownToStartAnimation = new Animation() { @Override public void applyTransformation(float interpolatedTime, Transformation t) { float targetScale = (mStartingScale + (-mStartingScale * interpolatedTime)); setAnimationProgress(targetScale); moveToStart(interpolatedTime); } }; mScaleDownToStartAnimation.setDuration(SCALE_DOWN_DURATION); if (listener != null) { mSpinner.setAnimationListener(listener); } mSpinner.clearAnimation(); mSpinner.startAnimation(mScaleDownToStartAnimation); } private void setTargetOffsetTopAndBottom(int offset, boolean requiresUpdate) { mSpinner.bringToFront(); mSpinner.offsetTopAndBottom(offset); if (mViewListener != null) { mViewListener.onOffset(offset); } mCurrentTargetOffsetTop = mSpinner.getTop(); if (requiresUpdate && android.os.Build.VERSION.SDK_INT < 11) { invalidate(); } } private void onSecondaryPointerUp(MotionEvent ev) { final int pointerIndex = MotionEventCompat.getActionIndex(ev); final int pointerId = MotionEventCompat.getPointerId(ev, pointerIndex); if (pointerId == mActivePointerId) { // This was our active pointer going up. Choose a new // active pointer and adjust accordingly. final int newPointerIndex = pointerIndex == 0 ? 1 : 0; mActivePointerId = MotionEventCompat.getPointerId(ev, newPointerIndex); } } /** * * @param listener the class that will receive the callback with an offset that the view should move. */ public void setOffsetViewListener(OffsetViewListener listener) { mViewListener = listener; } /** * Classes that wish to be notified when the swipe gesture correctly * triggers a refresh should implement this interface. */ public interface OnRefreshListener { void onRefresh(); } /** * Classes that wants to offset one of its view along with the spinner should * implement this interface */ public interface OffsetViewListener { /** * Called whenever the spinner is offsetting */ void onOffset(int offset); } }