package com.tweetlanes.android.core.widget.pulltorefresh; import android.content.Context; import android.content.res.TypedArray; import android.graphics.Color; import android.os.Handler; import android.util.AttributeSet; import android.view.MotionEvent; import android.view.View; import android.view.ViewConfiguration; import android.view.ViewGroup; import android.view.animation.AccelerateDecelerateInterpolator; import android.view.animation.Interpolator; import android.widget.LinearLayout; import com.tweetlanes.android.core.R; import com.tweetlanes.android.core.widget.pulltorefresh.internal.LoadingLayout; public abstract class PullToRefreshBase<T extends View> extends LinearLayout { final class SmoothScrollRunnable implements Runnable { static final int ANIMATION_DURATION_MS = 190; static final int ANIMATION_FPS = 1000 / 60; private final Interpolator mInterpolator; private final int mScrollToY; private final int mScrollFromY; private final Handler mHandler; private boolean mContinueRunning = true; private long mStartTime = -1; private int mCurrentY = -1; public SmoothScrollRunnable(Handler handler, int fromY, int toY) { this.mHandler = handler; this.mScrollFromY = fromY; this.mScrollToY = toY; this.mInterpolator = new AccelerateDecelerateInterpolator(); } @Override public void run() { /** * Only set startTime if this is the first time we're starting, else * actually calculate the Y delta */ if (mStartTime == -1) { mStartTime = System.currentTimeMillis(); } else { /** * We do do all calculations in long to reduce software float * calculations. We use 1000 as it gives us good accuracy and * small rounding errors */ long normalizedTime = (1000 * (System.currentTimeMillis() - mStartTime)) / ANIMATION_DURATION_MS; normalizedTime = Math.max(Math.min(normalizedTime, 1000), 0); final int deltaY = Math.round((mScrollFromY - mScrollToY) * mInterpolator .getInterpolation(normalizedTime / 1000f)); this.mCurrentY = mScrollFromY - deltaY; setHeaderScroll(mCurrentY); } // If we're not at the target Y, keep going... if (mContinueRunning && mScrollToY != mCurrentY) { mHandler.postDelayed(this, ANIMATION_FPS); } } public void stop() { this.mContinueRunning = false; this.mHandler.removeCallbacks(this); } } // =========================================================== // Constants // =========================================================== private static final float FRICTION = 2.0f; private static final int PULL_TO_REFRESH = 0x0; private static final int RELEASE_TO_REFRESH = 0x1; private static final int REFRESHING = 0x2; private static final int MANUAL_REFRESHING = 0x3; public static final int MODE_PULL_DOWN_TO_REFRESH = 0x1; public static final int MODE_PULL_UP_TO_REFRESH = 0x2; static final int MODE_BOTH = 0x3; // =========================================================== // Fields // =========================================================== private int mTouchSlop; private float mInitialMotionY; private float mLastMotionX; private float mLastMotionY; private boolean mIsBeingDragged = false; private int mState = PULL_TO_REFRESH; private int mMode = MODE_PULL_DOWN_TO_REFRESH; private int mCurrentMode; private boolean mDisableScrollingWhileRefreshing = true; T mRefreshableView; private boolean mIsPullToRefreshEnabled = true; private LoadingLayout mHeaderLayout; private LoadingLayout mFooterLayout; private int mHeaderHeight; private final Handler mHandler = new Handler(); private OnRefreshListener mOnRefreshListener; private SmoothScrollRunnable mCurrentSmoothScrollRunnable; // =========================================================== // Constructors // =========================================================== PullToRefreshBase(Context context) { super(context); init(context, null); } PullToRefreshBase(Context context, int mode) { super(context); this.mMode = mode; init(context, null); } PullToRefreshBase(Context context, AttributeSet attrs) { super(context, attrs); init(context, attrs); } // =========================================================== // Getter & Setter // =========================================================== /** * Deprecated. Use {@link #getRefreshableView()} from now on. * * @return The Refreshable View which is currently wrapped * @deprecated */ public final T getAdapterView() { return mRefreshableView; } /** * Get the Wrapped Refreshable View. Anything returned here has already been * added to the content view. * * @return The View which is currently wrapped */ public final T getRefreshableView() { return mRefreshableView; } /** * Whether Pull-to-Refresh is enabled * * @return enabled */ public final boolean isPullToRefreshEnabled() { return mIsPullToRefreshEnabled; } /** * Returns whether the widget has disabled scrolling on the Refreshable View * while refreshing. * * @param true if the widget has disabled scrolling while refreshing */ public final boolean isDisableScrollingWhileRefreshing() { return mDisableScrollingWhileRefreshing; } /** * Returns whether the Widget is currently in the Refreshing state * * @return true if the Widget is currently refreshing */ final boolean isRefreshing() { return mState == REFRESHING || mState == MANUAL_REFRESHING; } /** * By default the Widget disabled scrolling on the Refreshable View while * refreshing. This method can change this behaviour. * * @param disableScrollingWhileRefreshing - true if you want to disable scrolling while refreshing */ final void setDisableScrollingWhileRefreshing( boolean disableScrollingWhileRefreshing) { this.mDisableScrollingWhileRefreshing = disableScrollingWhileRefreshing; } /** * Mark the current Refresh as complete. Will Reset the UI and hide the * Refreshing View */ public final void onRefreshComplete() { if (mState != PULL_TO_REFRESH) { resetHeader(); } } /** * Set OnRefreshListener for the Widget * * @param listener - Listener to be used when the Widget is set to Refresh */ public final void setOnRefreshListener(OnRefreshListener listener) { mOnRefreshListener = listener; } /** * A mutator to enable/disable Pull-to-Refresh for the current View * * @param enable Whether Pull-To-Refresh should be used */ public final void setPullToRefreshEnabled(boolean enable) { this.mIsPullToRefreshEnabled = enable; } /** * Set Text to show when the Widget is being pulled, and will refresh when * released * * @param releaseLabel - String to display */ void setReleaseLabel(String releaseLabel) { if (null != mHeaderLayout) { mHeaderLayout.setReleaseLabel(releaseLabel); } if (null != mFooterLayout) { mFooterLayout.setReleaseLabel(releaseLabel); } } /** * Set Text to show when the Widget is being Pulled * * @param pullLabel - String to display */ void setPullLabel(String pullLabel) { if (null != mHeaderLayout) { mHeaderLayout.setPullLabel(pullLabel); } if (null != mFooterLayout) { mFooterLayout.setPullLabel(pullLabel); } } /** * Set Text to show when the Widget is refreshing * * @param refreshingLabel - String to display */ void setRefreshingLabel(String refreshingLabel) { if (null != mHeaderLayout) { mHeaderLayout.setRefreshingLabel(refreshingLabel); } if (null != mFooterLayout) { mFooterLayout.setRefreshingLabel(refreshingLabel); } } final void setRefreshing() { this.setRefreshing(true); } /** * Sets the Widget to be in the refresh state. The UI will be updated to * show the 'Refreshing' view. * * @param doScroll - true if you want to force a scroll to the Refreshing view. */ public final void setRefreshing(boolean doScroll) { if (!isRefreshing()) { setRefreshingInternal(doScroll); mState = MANUAL_REFRESHING; } } public final boolean hasPullFromTop() { return mCurrentMode != MODE_PULL_UP_TO_REFRESH; } public final boolean showingRefreshUI() { return mCurrentMode != 0; } // =========================================================== // Methods for/from SuperClass/Interfaces // =========================================================== @Override public final boolean onTouchEvent(MotionEvent event) { if (!mIsPullToRefreshEnabled) { return false; } if (isRefreshing() && mDisableScrollingWhileRefreshing) { return true; } if (event.getAction() == MotionEvent.ACTION_DOWN && event.getEdgeFlags() != 0) { return false; } switch (event.getAction()) { case MotionEvent.ACTION_MOVE: { if (mIsBeingDragged) { mLastMotionY = event.getY(); this.pullEvent(); return true; } break; } case MotionEvent.ACTION_DOWN: { if (isReadyForPull()) { mLastMotionY = mInitialMotionY = event.getY(); return true; } break; } case MotionEvent.ACTION_CANCEL: case MotionEvent.ACTION_UP: { if (mIsBeingDragged) { mIsBeingDragged = false; if (mState == RELEASE_TO_REFRESH && null != mOnRefreshListener) { setRefreshingInternal(true); mOnRefreshListener.onRefresh(); } else { smoothScrollTo(0); } return true; } break; } } return false; } @Override public final boolean onInterceptTouchEvent(MotionEvent event) { if (!mIsPullToRefreshEnabled) { return false; } if (isRefreshing() && mDisableScrollingWhileRefreshing) { return true; } final int action = event.getAction(); if (action == MotionEvent.ACTION_CANCEL || action == MotionEvent.ACTION_UP) { mIsBeingDragged = false; return false; } if (action != MotionEvent.ACTION_DOWN && mIsBeingDragged) { return true; } switch (action) { case MotionEvent.ACTION_MOVE: { if (isReadyForPull()) { final float y = event.getY(); final float dy = y - mLastMotionY; final float yDiff = Math.abs(dy); final float xDiff = Math.abs(event.getX() - mLastMotionX); if (yDiff > mTouchSlop && yDiff > xDiff) { if ((mMode == MODE_PULL_DOWN_TO_REFRESH || mMode == MODE_BOTH) && dy >= 0.0001f && isReadyForPullDown()) { mLastMotionY = y; mIsBeingDragged = true; if (mMode == MODE_BOTH) { mCurrentMode = MODE_PULL_DOWN_TO_REFRESH; } } else if ((mMode == MODE_PULL_UP_TO_REFRESH || mMode == MODE_BOTH) && dy <= 0.0001f && isReadyForPullUp()) { mLastMotionY = y; mIsBeingDragged = true; if (mMode == MODE_BOTH) { mCurrentMode = MODE_PULL_UP_TO_REFRESH; } } } } break; } case MotionEvent.ACTION_DOWN: { if (isReadyForPull()) { mLastMotionY = mInitialMotionY = event.getY(); mLastMotionX = event.getX(); mIsBeingDragged = false; } break; } } return mIsBeingDragged; } void addRefreshableView(Context context, T refreshableView) { addView(refreshableView, new LinearLayout.LayoutParams( LayoutParams.FILL_PARENT, 0, 1.0f)); } /** * This is implemented by derived classes to return the created View. If you * need to use a custom View (such as a custom ListView), override this * method and return an instance of your custom class. * <p/> * Be sure to set the ID of the view in this method, especially if you're * using a ListActivity or ListFragment. * * @param context * @param attrs AttributeSet from wrapped class. Means that anything you * include in the XML layout declaration will be routed to the * created View * @return New instance of the Refreshable View */ protected abstract T createRefreshableView(Context context, AttributeSet attrs); final int getCurrentMode() { return mCurrentMode; } final LoadingLayout getFooterLayout() { return mFooterLayout; } final LoadingLayout getHeaderLayout() { return mHeaderLayout; } final int getHeaderHeight() { return mHeaderHeight; } final int getMode() { return mMode; } /** * Implemented by derived class to return whether the View is in a state * where the user can Pull to Refresh by scrolling down. * * @return true if the View is currently the correct state (for example, top * of a ListView) */ protected abstract boolean isReadyForPullDown(); /** * Implemented by derived class to return whether the View is in a state * where the user can Pull to Refresh by scrolling up. * * @return true if the View is currently in the correct state (for example, * bottom of a ListView) */ protected abstract boolean isReadyForPullUp(); // =========================================================== // Methods // =========================================================== void resetHeader() { mState = PULL_TO_REFRESH; mIsBeingDragged = false; if (null != mHeaderLayout) { mHeaderLayout.reset(); } if (null != mFooterLayout) { mFooterLayout.reset(); } smoothScrollTo(0); } void setRefreshingInternal(boolean doScroll) { mState = REFRESHING; if (null != mHeaderLayout) { mHeaderLayout.refreshing(); } if (null != mFooterLayout) { mFooterLayout.refreshing(); } if (doScroll) { smoothScrollTo(mCurrentMode == MODE_PULL_DOWN_TO_REFRESH ? -mHeaderHeight : mHeaderHeight); } } final void setHeaderScroll(int y) { scrollTo(0, y); } final void smoothScrollTo(int y) { if (null != mCurrentSmoothScrollRunnable) { mCurrentSmoothScrollRunnable.stop(); } if (this.getScrollY() != y) { this.mCurrentSmoothScrollRunnable = new SmoothScrollRunnable( mHandler, getScrollY(), y); mHandler.post(mCurrentSmoothScrollRunnable); } } private void init(Context context, AttributeSet attrs) { setOrientation(LinearLayout.VERTICAL); mTouchSlop = ViewConfiguration.getTouchSlop(); // Styleables from XML TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.PullToRefresh); if (a.hasValue(R.styleable.PullToRefresh_mode)) { mMode = a.getInteger(R.styleable.PullToRefresh_mode, MODE_PULL_DOWN_TO_REFRESH); } // Refreshable View // By passing the attrs, we can add ListView/GridView params via XML mRefreshableView = this.createRefreshableView(context, attrs); this.addRefreshableView(context, mRefreshableView); // Loading View Strings String pullLabel = context .getString(R.string.pull_to_refresh_pull_label); String refreshingLabel = context .getString(R.string.pull_to_refresh_refreshing_label); String releaseLabel = context .getString(R.string.pull_to_refresh_release_label); // Add Loading Views if (mMode == MODE_PULL_DOWN_TO_REFRESH || mMode == MODE_BOTH) { mHeaderLayout = new LoadingLayout(context, MODE_PULL_DOWN_TO_REFRESH, releaseLabel, pullLabel, refreshingLabel); addView(mHeaderLayout, 0, new LinearLayout.LayoutParams( ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT)); measureView(mHeaderLayout); mHeaderHeight = mHeaderLayout.getMeasuredHeight(); } if (mMode == MODE_PULL_UP_TO_REFRESH || mMode == MODE_BOTH) { mFooterLayout = new LoadingLayout(context, MODE_PULL_UP_TO_REFRESH, releaseLabel, pullLabel, refreshingLabel); addView(mFooterLayout, new LinearLayout.LayoutParams( ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT)); measureView(mFooterLayout); mHeaderHeight = mFooterLayout.getMeasuredHeight(); } // Styleables from XML if (a.hasValue(R.styleable.PullToRefresh_headerTextColor)) { final int color = a.getColor( R.styleable.PullToRefresh_headerTextColor, Color.BLACK); if (null != mHeaderLayout) { mHeaderLayout.setTextColor(color); } if (null != mFooterLayout) { mFooterLayout.setTextColor(color); } } if (a.hasValue(R.styleable.PullToRefresh_headerBackground)) { this.setBackgroundResource(a.getResourceId( R.styleable.PullToRefresh_headerBackground, Color.WHITE)); } if (a.hasValue(R.styleable.PullToRefresh_adapterViewBackground)) { mRefreshableView.setBackgroundResource(a.getResourceId( R.styleable.PullToRefresh_adapterViewBackground, Color.WHITE)); } a.recycle(); // Hide Loading Views switch (mMode) { case MODE_BOTH: setPadding(0, -mHeaderHeight, 0, -mHeaderHeight); break; case MODE_PULL_UP_TO_REFRESH: setPadding(0, 0, 0, -mHeaderHeight); break; case MODE_PULL_DOWN_TO_REFRESH: default: setPadding(0, -mHeaderHeight, 0, 0); break; } // If we're not using MODE_BOTH, then just set currentMode to current // mode if (mMode != MODE_BOTH) { mCurrentMode = mMode; } } private static void measureView(View child) { ViewGroup.LayoutParams p = child.getLayoutParams(); if (p == null) { p = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT); } int childWidthSpec = ViewGroup.getChildMeasureSpec(0, 0, p.width); int lpHeight = p.height; int childHeightSpec; if (lpHeight > 0) { childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight, MeasureSpec.EXACTLY); } else { childHeightSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); } child.measure(childWidthSpec, childHeightSpec); } /** * Actions a Pull Event * * @return true if the Event has been handled, false if there has been no * change */ private boolean pullEvent() { final int newHeight; final int oldHeight = this.getScrollY(); switch (mCurrentMode) { case MODE_PULL_UP_TO_REFRESH: newHeight = Math.round(Math.max(mInitialMotionY - mLastMotionY, 0) / FRICTION); break; case MODE_PULL_DOWN_TO_REFRESH: default: newHeight = Math.round(Math.min(mInitialMotionY - mLastMotionY, 0) / FRICTION); break; } setHeaderScroll(newHeight); if (newHeight != 0) { if (mState == PULL_TO_REFRESH && mHeaderHeight < Math.abs(newHeight)) { mState = RELEASE_TO_REFRESH; switch (mCurrentMode) { case MODE_PULL_UP_TO_REFRESH: mFooterLayout.releaseToRefresh(); break; case MODE_PULL_DOWN_TO_REFRESH: mHeaderLayout.releaseToRefresh(); break; } return true; } else if (mState == RELEASE_TO_REFRESH && mHeaderHeight >= Math.abs(newHeight)) { mState = PULL_TO_REFRESH; switch (mCurrentMode) { case MODE_PULL_UP_TO_REFRESH: mFooterLayout.pullToRefresh(); break; case MODE_PULL_DOWN_TO_REFRESH: mHeaderLayout.pullToRefresh(); break; } return true; } } return oldHeight != newHeight; } private boolean isReadyForPull() { switch (mMode) { case MODE_PULL_DOWN_TO_REFRESH: return isReadyForPullDown(); case MODE_PULL_UP_TO_REFRESH: return isReadyForPullUp(); case MODE_BOTH: return isReadyForPullUp() || isReadyForPullDown(); } return false; } // =========================================================== // Inner and Anonymous Classes // =========================================================== public static interface OnRefreshListener { public void onRefresh(); } public static interface OnLastItemVisibleListener { public void onLastItemVisible(); } @Override public void setLongClickable(boolean longClickable) { getRefreshableView().setLongClickable(longClickable); } }