Skip to content

Instantly share code, notes, and snippets.

Embed
What would you like to do?
/*
* Copyright 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.example.android.swiperefreshmultipleviews;
import android.content.Context;
import android.support.v4.view.ViewCompat;
import android.support.v4.widget.SwipeRefreshLayout;
import android.util.AttributeSet;
import android.view.View;
import android.widget.AbsListView;
/**
* A descendant of {@link android.support.v4.widget.SwipeRefreshLayout} which supports multiple
* child views triggering a refresh gesture. You set the views which can trigger the gesture via
* {@link #setSwipeableChildren(int...)}, providing it the child ids.
*/
public class MultiSwipeRefreshLayout extends SwipeRefreshLayout {
private View[] mSwipeableChildren;
public MultiSwipeRefreshLayout(Context context) {
super(context);
}
public MultiSwipeRefreshLayout(Context context, AttributeSet attrs) {
super(context, attrs);
}
/**
* Set the children which can trigger a refresh by swiping down when they are visible. These
* views need to be a descendant of this view.
*/
public void setSwipeableChildren(final int... ids) {
assert ids != null;
// Iterate through the ids and find the Views
mSwipeableChildren = new View[ids.length];
for (int i = 0; i < ids.length; i++) {
mSwipeableChildren[i] = findViewById(ids[i]);
}
}
// BEGIN_INCLUDE(can_child_scroll_up)
/**
* This method controls when the swipe-to-refresh gesture is triggered. By returning false here
* we are signifying that the view is in a state where a refresh gesture can start.
*
* <p>As {@link android.support.v4.widget.SwipeRefreshLayout} only supports one direct child by
* default, we need to manually iterate through our swipeable children to see if any are in a
* state to trigger the gesture. If so we return false to start the gesture.
*/
@Override
public boolean canChildScrollUp() {
if (mSwipeableChildren != null && mSwipeableChildren.length > 0) {
// Iterate through the scrollable children and check if any of them can not scroll up
for (View view : mSwipeableChildren) {
if (view != null && view.isShown() && !canViewScrollUp(view)) {
// If the view is shown, and can not scroll upwards, return false and start the
// gesture.
return false;
}
}
}
return true;
}
// END_INCLUDE(can_child_scroll_up)
// BEGIN_INCLUDE(can_view_scroll_up)
/**
* Utility method to check whether a {@link View} can scroll up from it's current position.
* Handles platform version differences, providing backwards compatible functionality where
* needed.
*/
private static boolean canViewScrollUp(View view) {
if (android.os.Build.VERSION.SDK_INT >= 14) {
// For ICS and above we can call canScrollVertically() to determine this
return ViewCompat.canScrollVertically(view, -1);
} else {
if (view instanceof AbsListView) {
// Pre-ICS we need to manually check the first visible item and the child view's top
// value
final AbsListView listView = (AbsListView) view;
return listView.getChildCount() > 0 &&
(listView.getFirstVisiblePosition() > 0
|| listView.getChildAt(0).getTop() < listView.getPaddingTop());
} else {
// For all other view types we just check the getScrollY() value
return view.getScrollY() > 0;
}
}
}
// END_INCLUDE(can_view_scroll_up)
}
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
You can’t perform that action at this time.