/*
* Copyright 2013 Chris Banes
*
* 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 uk.co.senab.actionbarpulltorefresh.library;
import android.app.Activity;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.PixelFormat;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.os.Build;
import android.util.Log;
import android.util.TypedValue;
import android.view.LayoutInflater;
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.AnimationUtils;
import android.view.animation.Interpolator;
import android.widget.FrameLayout;
import android.widget.ProgressBar;
import android.widget.TextView;
/**
* FIXME
*/
public class PullToRefreshAttacher implements View.OnTouchListener {
/**
* Default configuration values
*/
private static final int DEFAULT_HEADER_LAYOUT = R.layout.default_header;
private static final int DEFAULT_ANIM_HEADER_IN = R.anim.fade_in;
private static final int DEFAULT_ANIM_HEADER_OUT = R.anim.fade_out;
private static final float DEFAULT_REFRESH_SCROLL_DISTANCE = 0.5f;
private static final boolean DEBUG = false;
private static final String LOG_TAG = "PullToRefreshAttacher";
private final EnvironmentDelegate mEnvironmentDelegate;
private final HeaderTransformer mHeaderTransformer;
private final View mHeaderView;
private final Animation mHeaderInAnimation, mHeaderOutAnimation;
private final int mTouchSlop;
private final float mRefreshScrollDistance;
private float mInitialMotionY, mLastMotionY, mPullBeginY;
private boolean mIsBeingDragged, mIsRefreshing, mIsHandlingTouchEvent;
private View mRefreshableView;
private ViewDelegate mViewDelegate;
private OnRefreshListener mRefreshListener;
private boolean mEnabled = true;
/**
* FIXME
* @param activity
*/
public PullToRefreshAttacher(Activity activity) {
this(activity, new Options());
}
/**
* FIXME
* @param activity
* @param options
*/
public PullToRefreshAttacher(Activity activity, Options options) {
if (options == null) {
Log.i(LOG_TAG, "Given null options so using default options.");
options = new Options();
}
// Copy necessary values from options
mRefreshScrollDistance = options.refreshScrollDistance;
// EnvironmentDelegate
mEnvironmentDelegate = options.environmentDelegate != null
? options.environmentDelegate
: createDefaultEnvironmentDelegate();
// Header Transformer
mHeaderTransformer = options.headerTransformer != null
? options.headerTransformer
: createDefaultHeaderTransformer();
// Create animations for use later
mHeaderInAnimation = AnimationUtils.loadAnimation(activity, options.headerInAnimation);
mHeaderOutAnimation = AnimationUtils.loadAnimation(activity, options.headerOutAnimation);
if (mHeaderOutAnimation != null) {
mHeaderOutAnimation.setAnimationListener(new AnimationCallback());
}
// Get touch slop for use later
mTouchSlop = ViewConfiguration.get(activity).getScaledTouchSlop();
// Get Window Decor View
final ViewGroup decorView = (ViewGroup) activity.getWindow().getDecorView();
// Create Header view and then add to Decor View
mHeaderView = LayoutInflater.from(mEnvironmentDelegate.getContextForInflater(activity))
.inflate(options.headerLayout, decorView, false);
if (mHeaderView == null) {
throw new IllegalArgumentException("Must supply valid layout id for header.");
}
mHeaderView.setVisibility(View.GONE);
// Create DecorChildLayout which will move all of the system's decor view's children + the
// Header View to itself. See DecorChildLayout for more info.
DecorChildLayout decorContents = new DecorChildLayout(activity, decorView, mHeaderView);
// Now add the DecorChildLayout to the decor view
decorView.addView(decorContents, ViewGroup.LayoutParams.MATCH_PARENT,
ViewGroup.LayoutParams.MATCH_PARENT);
// Notify transformer
mHeaderTransformer.onViewCreated(activity, mHeaderView);
}
/**
* Set the view which will be used to initiate refresh requests and a listener to be invoked
* when a refresh is started. This version of the method will try to find a handler for the
* view from the built-in view delegates.
*
* @param view - View which will be used to initiate refresh requests.
* @param refreshListener - Listener to be invoked when a refresh is started.
*/
public void setRefreshableView(View view, OnRefreshListener refreshListener) {
setRefreshableView(view, null, refreshListener);
}
/**
* Set the view which will be used to initiate refresh requests, along with a delegate which
* knows how to handle the given view, and a listener to be invoked when a refresh is started.
*
* @param view - View which will be used to initiate refresh requests.
* @param viewDelegate - delegate which knows how to handle <code>view</code>.
* @param refreshListener - Listener to be invoked when a refresh is started.
*/
public void setRefreshableView(View view, ViewDelegate viewDelegate,
OnRefreshListener refreshListener) {
// If we already have a refreshable view, reset it and our state
if (mRefreshableView != null) {
mRefreshableView.setOnTouchListener(null);
setRefreshingInt(false, false);
}
// Update Refresh Listener
mRefreshListener = refreshListener;
// Check to see if view is null
if (view == null) {
Log.i(LOG_TAG, "Refreshable View is null.");
mViewDelegate = null;
return;
}
// View to detect refreshes for
mRefreshableView = view;
mRefreshableView.setOnTouchListener(this);
// ViewDelegate
if (viewDelegate == null) {
viewDelegate = InstanceCreationUtils.getBuiltInViewDelegate(view);
if (viewDelegate == null) {
throw new IllegalArgumentException("No view handler found. Please provide one.");
}
}
mViewDelegate = viewDelegate;
}
/**
* Manually set this Attacher's refreshing state. The header will be displayed or hidden as
* requested.
* @param refreshing - Whether the attacher should be in a refreshing state,
*/
public final void setRefreshing(boolean refreshing) {
setRefreshingInt(refreshing, false);
}
/**
* @return true if this Attacher is currently in a refreshing state.
*/
public final boolean isRefreshing() {
return mIsRefreshing;
}
/**
* @return true if this PullToRefresh is currently enabled (defaults to <code>true</code>)
*/
public boolean isEnabled() {
return mEnabled;
}
/**
* Allows the enable/disable of this PullToRefreshAttacher. If disabled when refreshing then
* the UI is automatically reset.
*
* @param enabled - Whether this PullToRefreshAttacher is enabled.
*/
public void setEnabled(boolean enabled) {
mEnabled = enabled;
if (!enabled) {
// If we're not enabled, reset any touch handling
resetTouch();
// If we're currently refreshing, reset the ptr UI
if (mIsRefreshing) {
reset(false);
}
}
}
/**
* Call this when your refresh is complete and this view should reset itself (header view
* will be hidden).
*
* This is the equivalent of calling <code>setRefreshing(false)</code>.
*/
public final void setRefreshComplete() {
setRefreshingInt(false, false);
}
/**
* @return The HeaderTransformer currently used by this Attacher.
*/
public HeaderTransformer getHeaderTransformer() {
return mHeaderTransformer;
}
@Override
public final boolean onTouch(View view, MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_DOWN && event.getEdgeFlags() != 0) {
return false;
}
// If we're not enabled don't handle any touch events
if (!isEnabled()) {
return false;
}
switch (event.getAction()) {
case MotionEvent.ACTION_MOVE: {
// If we're already refreshing ignore it
if (mIsRefreshing) {
return false;
}
final float y = event.getY();
// As there are times when we are not given the ACTION_DOWN, we need to check here
// whether we should handle the event
if (!mIsHandlingTouchEvent) {
if (canRefresh(true) && mViewDelegate.isScrolledToTop(mRefreshableView)) {
mIsHandlingTouchEvent = true;
mInitialMotionY = y;
} else {
// We're still not handling the event, so fail-fast
return false;
}
}
// We're not currently being dragged so check to see if the user has scrolled enough
if (!mIsBeingDragged && (y - mInitialMotionY) > mTouchSlop) {
mIsBeingDragged = true;
onPullStarted(y);
}
if (mIsBeingDragged) {
final float yDx = y - mLastMotionY;
/**
* Check to see if the user is scrolling the right direction (down).
* We allow a small scroll up which is the check against negative touch slop.
*/
if (yDx >= -mTouchSlop) {
onPull(y);
// Only record the y motion if the user has scrolled down.
if (yDx > 0f) {
mLastMotionY = y;
}
} else {
resetTouch();
}
}
break;
}
case MotionEvent.ACTION_DOWN: {
// If we're already refreshing, ignore
if (canRefresh(true) && mViewDelegate.isScrolledToTop(mRefreshableView)) {
mIsHandlingTouchEvent = true;
mInitialMotionY = event.getY();
}
break;
}
case MotionEvent.ACTION_CANCEL:
case MotionEvent.ACTION_UP: {
resetTouch();
break;
}
}
// Always return false as we only want to observe events
return false;
}
private void resetTouch() {
if (mIsBeingDragged) {
// We were being dragged, but not any more.
mIsBeingDragged = false;
onPullEnded();
}
mIsHandlingTouchEvent = false;
mInitialMotionY = mLastMotionY = mPullBeginY = 0f;
}
void onPullStarted(float y) {
if (DEBUG) {
Log.d(LOG_TAG, "onPullStarted");
}
// Show Header
if (mHeaderInAnimation != null) {
mHeaderView.startAnimation(mHeaderInAnimation);
}
mHeaderView.setVisibility(View.VISIBLE);
mPullBeginY = y;
}
void onPull(float y) {
if (DEBUG) {
Log.d(LOG_TAG, "onPull");
}
final float pxScrollForRefresh = mRefreshableView.getHeight() * mRefreshScrollDistance;
final float scrollLength = y - mPullBeginY;
if (scrollLength < pxScrollForRefresh) {
mHeaderTransformer.onPulled(scrollLength / pxScrollForRefresh);
} else {
setRefreshingInt(true, true);
}
}
void onPullEnded() {
if (DEBUG) {
Log.d(LOG_TAG, "onPullEnded");
}
if (!mIsRefreshing) {
reset(true);
}
}
protected EnvironmentDelegate createDefaultEnvironmentDelegate() {
return new EnvironmentDelegate();
}
protected HeaderTransformer createDefaultHeaderTransformer() {
return new DefaultHeaderTransformer();
}
private void setRefreshingInt(boolean refreshing, boolean fromTouch) {
if (DEBUG) {
Log.d(LOG_TAG, "setRefreshingInt: " + refreshing);
}
// Check to see if we need to do anything
if (mIsRefreshing == refreshing) {
return;
}
if (refreshing && canRefresh(fromTouch)) {
startRefresh(fromTouch);
} else {
reset(fromTouch);
}
}
/**
* @param fromTouch - Whether this is being invoked from a touch event
* @return true if we're currently in a state where a refresh can be started.
*/
private boolean canRefresh(boolean fromTouch) {
return !mIsRefreshing && (!fromTouch || mRefreshListener != null);
}
private void reset(boolean fromTouch) {
// Update isRefreshing state
mIsRefreshing = false;
if (mHeaderView.getVisibility() != View.GONE) {
// Hide Header
if (mHeaderOutAnimation != null) {
mHeaderView.startAnimation(mHeaderOutAnimation);
// HeaderTransformer.onReset() is called once the animation has finished
} else {
// As we're not animating, hide the header + call the header transformer now
mHeaderView.setVisibility(View.GONE);
mHeaderTransformer.onReset();
}
}
}
private void startRefresh(boolean fromTouch) {
// Update isRefreshing state
mIsRefreshing = true;
// Call OnRefreshListener if this call has originated from a touch event
if (fromTouch) {
mRefreshListener.onRefreshStarted(mRefreshableView);
}
// Call Transformer
mHeaderTransformer.onRefreshStarted();
// Make sure header is visible.
if (mHeaderView.getVisibility() != View.VISIBLE) {
if (mHeaderInAnimation != null) {
mHeaderView.startAnimation(mHeaderInAnimation);
}
mHeaderView.setVisibility(View.VISIBLE);
}
}
/**
* Simple Listener to listen for any callbacks to Refresh.
*/
public interface OnRefreshListener {
/**
* Called when the user has initiated a refresh by pulling.
* @param view - View which the user has started the refresh from.
*/
public void onRefreshStarted(View view);
}
public static abstract class HeaderTransformer {
/**
* Called whether the header view has been inflated from the resources defined in
* {@link Options#headerLayout}.
*
* @param headerView - inflated header view.
*/
public abstract void onViewCreated(Activity activity, View headerView);
/**
* Called when the header should be reset. You should update any child views to reflect this.
* <p/>
* You should <strong>not</strong> change the
* visibility of the header view.
*/
public abstract void onReset();
/**
* Called the user has pulled on the scrollable view.
* @param percentagePulled - value between 0.0f and 1.0f depending on how far the user has pulled.
*/
public abstract void onPulled(float percentagePulled);
/**
* Called when a refresh has begun. Theoretically this call is similar to that provided
* from {@link OnRefreshListener} but is more suitable for header view updates.
*/
public abstract void onRefreshStarted();
}
/**
* FIXME
*/
public static abstract class ViewDelegate {
/**
* Allows you to provide support for View which do not have built-in support. In this
* method you should cast <code>view</code> to it's native class, and check if it is
* scrolled to the top.
*
* @param view The view which has should be checked against.
* @return true if <code>view</code> is scrolled to the top.
*/
public abstract boolean isScrolledToTop(View view);
}
/**
* FIXME
*/
public static class EnvironmentDelegate {
/**
* @return Context which should be used for inflating the header layout
*/
public Context getContextForInflater(Activity activity) {
if (Build.VERSION.SDK_INT >= 14) {
return activity.getActionBar().getThemedContext();
} else {
return activity;
}
}
}
public static final class Options {
/**
* EnvironmentDelegate instance which will be used. If null, we will create an instance of
* the default class.
*/
public EnvironmentDelegate environmentDelegate = null;
/**
* The layout resource ID which should be inflated to be displayed above the Action Bar
*/
public int headerLayout = DEFAULT_HEADER_LAYOUT;
/**
* The header transformer to be used to transfer the header view. If null, an instance of
* {@link DefaultHeaderTransformer} will be used.
*/
public HeaderTransformer headerTransformer = null;
/**
* The anim resource ID which should be started when the header is being hidden.
*/
public int headerOutAnimation = DEFAULT_ANIM_HEADER_OUT;
/**
* The anim resource ID which should be started when the header is being shown.
*/
public int headerInAnimation = DEFAULT_ANIM_HEADER_IN;
/**
* The percentage of the refreshable view that needs to be scrolled before a refresh
* is initiated.
*/
public float refreshScrollDistance = DEFAULT_REFRESH_SCROLL_DISTANCE;
}
private class AnimationCallback implements Animation.AnimationListener {
@Override
public void onAnimationStart(Animation animation) {
}
@Override
public void onAnimationEnd(Animation animation) {
if (animation == mHeaderOutAnimation) {
mHeaderView.setVisibility(View.GONE);
mHeaderTransformer.onReset();
}
}
@Override
public void onAnimationRepeat(Animation animation) {
}
}
/**
* Default Header Transformer.
*/
public static class DefaultHeaderTransformer extends HeaderTransformer {
private TextView mHeaderTextView;
private ProgressBar mHeaderProgressBar;
private CharSequence mPullRefreshLabel, mRefreshingLabel;
private final Interpolator mInterpolator = new AccelerateInterpolator();
@Override
public void onViewCreated(Activity activity, View headerView) {
// Get ProgressBar and TextView. Also set initial text on TextView
mHeaderProgressBar = (ProgressBar) headerView.findViewById(R.id.ptr_progress);
mHeaderTextView = (TextView) headerView.findViewById(R.id.ptr_text);
// Labels to display
mPullRefreshLabel = activity.getString(R.string.pull_to_refresh_pull_label);
mRefreshingLabel = activity.getString(R.string.pull_to_refresh_refreshing_label);
View contentView = headerView.findViewById(R.id.ptr_content);
if (contentView != null) {
contentView.getLayoutParams().height = getActionBarSize(activity);
contentView.requestLayout();
}
Drawable abBg = getActionBarBackground(activity);
if (abBg != null) {
// If we do not have a opaque background we just display a solid solid behind it
if (abBg.getOpacity() != PixelFormat.OPAQUE) {
View view = headerView.findViewById(R.id.ptr_text_opaque_bg);
if (view != null) {
view.setVisibility(View.VISIBLE);
}
}
mHeaderTextView.setBackgroundDrawable(abBg);
}
// Call onReset to make sure that the View is consistent
onReset();
}
@Override
public void onReset() {
// Reset Progress Bar
if (mHeaderProgressBar != null) {
mHeaderProgressBar.setVisibility(View.GONE);
mHeaderProgressBar.setProgress(0);
mHeaderProgressBar.setIndeterminate(false);
}
// Reset Text View
if (mHeaderTextView != null) {
mHeaderTextView.setVisibility(View.VISIBLE);
mHeaderTextView.setText(mPullRefreshLabel);
}
}
@Override
public void onPulled(float percentagePulled) {
if (mHeaderProgressBar != null) {
mHeaderProgressBar.setVisibility(View.VISIBLE);
final float progress = mInterpolator.getInterpolation(percentagePulled);
mHeaderProgressBar.setProgress(Math.round(mHeaderProgressBar.getMax() * progress));
}
}
@Override
public void onRefreshStarted() {
if (mHeaderTextView != null) {
mHeaderTextView.setText(mRefreshingLabel);
}
if (mHeaderProgressBar != null) {
mHeaderProgressBar.setVisibility(View.VISIBLE);
mHeaderProgressBar.setIndeterminate(true);
}
}
/**
* Set Text to show to prompt the user is pull (or keep pulling).
* @param pullText - Text to display.
*/
public void setPullText(CharSequence pullText) {
mPullRefreshLabel = pullText;
if (mHeaderTextView != null) {
mHeaderTextView.setText(mPullRefreshLabel);
}
}
/**
* Set Text to show to tell the user that a refresh is currently in progress.
* @param refreshingText - Text to display.
*/
public void setRefreshingText(CharSequence refreshingText) {
mRefreshingLabel = refreshingText;
}
protected Drawable getActionBarBackground(Context context) {
int[] android_styleable_ActionBar = { android.R.attr.background };
// Need to get resource id of style pointed to from actionBarStyle
TypedValue outValue = new TypedValue();
context.getTheme().resolveAttribute(android.R.attr.actionBarStyle, outValue, true);
// Now get action bar style values...
TypedArray abStyle = context.getTheme().obtainStyledAttributes(outValue.resourceId,
android_styleable_ActionBar);
try {
// background is the first attr in the array above so it's index is 0.
return abStyle.getDrawable(0);
} finally {
abStyle.recycle();
}
}
protected int getActionBarSize(Context context) {
int[] attrs = { android.R.attr.actionBarSize };
TypedArray values = context.getTheme().obtainStyledAttributes(attrs);
try {
return values.getDimensionPixelSize(0, 0);
} finally {
values.recycle();
}
}
}
/**
* This class allows us to insert a layer in between the system decor view and the actual decor.
* (e.g. Action Bar views). This is needed so we can receive a call to fitSystemWindows(Rect)
* so we can adjust the header view to fit the system windows too.
*/
final static class DecorChildLayout extends FrameLayout {
private ViewGroup mHeaderViewWrapper;
DecorChildLayout(Context context, ViewGroup systemDecorView, View headerView) {
super(context);
// Move all children from decor view to here
for (int i = 0, z = systemDecorView.getChildCount() ; i < z ; i++) {
View child = systemDecorView.getChildAt(i);
systemDecorView.removeView(child);
addView(child);
}
/**
* Wrap the Header View in a FrameLayout and add it to this view. It is wrapped
* so any inset changes do not affect the actual header view.
*/
mHeaderViewWrapper = new FrameLayout(context);
mHeaderViewWrapper.addView(headerView);
addView(mHeaderViewWrapper, ViewGroup.LayoutParams.MATCH_PARENT,
ViewGroup.LayoutParams.WRAP_CONTENT);
}
@Override
protected boolean fitSystemWindows(Rect insets) {
if (DEBUG) {
Log.d(LOG_TAG, "fitSystemWindows: " + insets.toString());
}
// Adjust the Header View's padding to take the insets into account
mHeaderViewWrapper.setPadding(insets.left, insets.top, insets.right, insets.bottom);
// Call return super so that the rest of the
return super.fitSystemWindows(insets);
}
}
}