android: How to disable scrolling on the viewpager [duplicate] - android

This question already has answers here:
How do disable paging by swiping with finger in ViewPager but still be able to swipe programmatically?
(27 answers)
Closed 6 years ago.
In my android application, I have a viewpager which have a list of imageView. Each of the view can be drawn. When I draw on it, I can still swipe to the next view from viewpager. How can I disable the paging while user start to draw on a an imageView.

Add this as a class and use it in xml instead of your viewpager tag. Basically we make a customised viewpager, where we are disabling the swipeable behaviour by returning false to onInterceptTouchEvent and OnTouchEvent.
public class NonSwipeableViewPager extends ViewPager {
public NonSwipeableViewPager(Context context) {
super(context);
}
public NonSwipeableViewPager(Context context, AttributeSet attrs) {
super(context, attrs);
}
#Override
public boolean onInterceptTouchEvent(MotionEvent event) {
// Never allow swiping to switch between pages
return false;
}
#Override
public boolean onTouchEvent(MotionEvent event) {
// Never allow swiping to switch between pages
return false;
}
}

Related

How to zoom/pan image while inside a scrollview

I am using a ViewPager with a TouchImageView inside it and it works great, (I have used this solution in many of my Android apps).
However I have an app for which there are many other controls on the same screen so they are all inside a scrollview control.
In this scenario I see the scrollview does not play nice and I am not able to pan within the zoomed image. When I use my finger to pan upward or downward the entire page scrolls instead of the image panning.
So here is what I am trying to do....
Inside the TouchImageView I detect Zoom Begin and Zoom End and have created an interface to make a callback to my Activity onZoomBegin() and onZoomEnd() methods.
In the onZoomBegin() method I want to disable the scrollview from responding to any touch events and in onZoomEnd() I can re-enable it.
So far here are the things I have tried doing in the onZoomBegin() method for which none are working....
scrollView.setEnabled(false);
scrollView.requestDisallowInterceptTouchEvent(true);
also I have tried the answer to a similar question which was to takeover the onTouchListener like such:
scrollView.setOnTouchListener(new View.OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
return true;
}
});
This does stop the scrollview from scrolling but the scrollview is still intercepting the touch events cause the image still will not pan up or down.
I've tried checking nestedScrollingEnabled in the layout designer, no joy....
I just want to know is there a way to totally disable a scrollview and then re-enable it from responding to touch events?
I found this answer on another question somewhere but by the time I realized it was the solution to my problem (answer to my question) then I lost reference to it. I will keep looking so I can edit this post to give credit where credit is due.
public class CustomScrollView extends ScrollView {
// true if we can scroll the ScrollView
// false if we cannot scroll
private boolean scrollable = true;
public CustomScrollView(Context context) {
super(context);
}
public CustomScrollView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public CustomScrollView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
public void setScrollingEnabled(boolean scrollable) {
this.scrollable = scrollable;
}
public boolean isScrollable() {
return scrollable;
}
#Override
public boolean onTouchEvent(MotionEvent ev) {
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN:
// if we can scroll pass the event to the superclass
if (scrollable)
return super.onTouchEvent(ev);
// only continue to handle the touch event if scrolling enabled
return false; // scrollable is always false at this point
default:
return super.onTouchEvent(ev);
}
}
#Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
// Don't do anything with intercepted touch events if
// we are not scrollable
if (!scrollable)
return false;
else
return super.onInterceptTouchEvent(ev);
}
}
This part I just figured out for myself.... In the TouchImageView I added a callback interface which is called when a zoom begins and ends so in my Activity I only had to do this:
private class OnZoomListener implements TouchImageView.OnZoomListener {
#Override
public void onZoomBegin() {
isZoomed = true;
scrollView.scrollTo(0, 0);
scrollView.setScrollingEnabled(false); // <-- disables scrollview
hideImageControls();
sizeViewPager();
}
#Override
public void onZoomEnd() {
scrollView.setScrollingEnabled(true); // <-- enables scrollview
showImageControls();
isZoomed = false;
}
}

Disable swipe on Viewpager, allow only Swipe on pagerTitleStrip

I am facing a problem on disabling the swipe gesture on viewpager fragment. Right now, I am using custom viewpager to disable the swipe gesture.
public class NonSwipeableViewPager extends ViewPager {
public NonSwipeableViewPager(Context context) {
super(context);
}
public NonSwipeableViewPager(Context context, AttributeSet attrs) {
super(context, attrs);
}
#Override
public boolean onInterceptTouchEvent(MotionEvent event) {
// Never allow swiping to switch between pages
return false;
}
#Override
public boolean onTouchEvent(MotionEvent event) {
// Never allow swiping to switch between pages
return false;
}
}
As result, this also will disable pagerTitleStrip. The reason I need to disable swipe gesture as one of my fragment contains a feature to remove item by swiping. It is possible to disable swipe only on viewpager but not on pagerTitleStrip?
PagerTitleStrip only shows title.
use PagerTabStrip instead of PagerTitleStrip.

Make swipes on one viewpager be set to another one

I have 2 view pagers in a linear layout both taking up same amount of screen. I want to make it so that if a user swipes any where on the screen then the swipe should only be for the lower viewpager. I tried increasing the touch delegate but that didn't work.
Well you're trying to some trippy stuff! I'd suggest making a CustomViewPager class for the 2nd viewpager which can have an instance of the 1st viewPager.
public class CustomViewPager extends ViewPager {
private ViewPager firstViewPager;
public CustomViewPager(Context context, AttributeSet attrs) {
super(context, attrs);
this.enabled = true;
}
#Override
public boolean onTouchEvent(MotionEvent event) {
if(firstViewPager!=null){
firstViewPager.onTouchEvent(event);
}
return super.onTouchEvent(event);
}
#Override
public boolean onInterceptTouchEvent(MotionEvent event) {
if(firstViewPager!=null){
firstViewPager.onInterceptTouchEvent(event);
}
return super.onInterceptTouchEvent(event);
}
public void setFirstViewPager(ViewPager firstViewPager) {
this.firstViewPager = firstViewPager;
}
}
In this you are passing the motion event that you get in the 2nd viewpager's onTouchEvent and onInterceptTouchEvent to the 1st viewpager. You'd also want to disable the swipe on the 1st viewpager that you could do as described here.

Android ViewPager scrolling issue with only one item when using getPageWidth from PagerAdapter

I have a ViewPager with a custom PagerAdapter that overwrites the method getPageWidth to return 0.3f, so I can show multiple pages in the screen, as suggested in the following blog:
http://commonsware.com/blog/2012/08/20/multiple-view-viewpager-options.html
In this case the ViewPager starts empty and the user starts filling the pages (images) as requested. The images are filled from left to right. All is working fine and the pages are dinamically created, and it is easy to swipe between them when there are multiple images.
However there is a problem when there are less than three pages instantiated. A swipe gesture from right (no content) to left produces a flickering with pages moving from left to right alternatively, as if the ViewPager were trying to move the first pages to right but later turning to its original position. This happens during the whole gesture, and stop when leaving the gesture. As I said this does not happen when there are pages enough to cover the whole screen width and a real scroll is necessary.
Any Ideas?
I know this is an old question, but I was just looking for a solution and came across this link (which oddly references this question). Anyway, I was able to figure out a solution based on their comments. The basic idea is to allow touch events based on the state of a boolean flag which you set.
Extend ViewPager on override onInterceptTouchEvent & onTouchEvent to only call super if you've set the flag. My class looks like this:
public class MyViewPager extends ViewPager {
private boolean isPagingEnabled = false;
public MyViewPager(Context context, AttributeSet attrs) {
super(context, attrs);
}
public MyViewPager(Context context) {
super(context);
}
#Override
public boolean onInterceptTouchEvent(MotionEvent event) {
if (isPagingEnabled) {
return super.onInterceptTouchEvent(event);
}
return false;
}
#Override
public boolean onTouchEvent(MotionEvent event) {
if (isPagingEnabled) {
return super.onTouchEvent(event);
}
return false;
}
public void setPagingEnabled(boolean pagingEnabled) {
isPagingEnabled = pagingEnabled;
}
}
In your layout xml, replace your com.android.support.v4.ViewPager elements with com.yourpackage.MyViewPager elements.
Since you return 0.3f from getPageWidth() in your pager adapter, you would want scrolling enabled when the fourth item has been added to it. The tricky part is having this line of code everywhere when you define your pager adapter, and add or remove any objects from the adapter backing list.
mPager.setPagingEnabled(items.size() > 3);
Rahuls solution works, but if you want auto enabling of paging according to content, you can modify ViewPager like this:
public class MyViewPager extends ViewPager {
public MyViewPager(Context context,
AttributeSet attrs) {
super(context, attrs);
}
public MyViewPager(Context context) {
super(context);
}
#Override
public boolean onInterceptTouchEvent(MotionEvent event) {
if (canScrollHorizontally(1)||canScrollHorizontally(-1)) {
return super.onInterceptTouchEvent(event);
}
return false;
}
#Override
public boolean onTouchEvent(MotionEvent event) {
if (canScrollHorizontally(1)||canScrollHorizontally(-1)) {
return super.onTouchEvent(event);
}
return false;
}
}
Now, if the ViewPager is scrollable, it will allow touches, otherwise disable.
I was able to solve it this way, in your getPageWidth() method,if there is only one image[you can get to know by checking size of array or arraylist] return 1, if the input size is greater than 1 return your decimal.
Here's the code to achieve this.
#override
public float getPageWidth(int position){
if(inpputsize==1){
return 1.0;
}
return 0.9;
}

Limited Swipe Area Android

I need to limit the swipe area inside a ViewPager. For example, if the user make the gesture to swipe on top half space of the screen it swipe to the next fragment, but if the user make the gesture on the bottom half of the screen it do nothing.
There is a way to do that?
This might be a what you need:
public class MyPager extends ViewPager {
public MyPager(Context context) {
super(context);
}
public MyPager(Context context, AttributeSet attrs) {
super(context, attrs);
}
#Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
if(inNeutralArea(ev.getX(),ev.getY())){
//--events re-directed to this ViewPager's onTouch() and to its child views from there--
return false;
}else {
//--events intercepted by this ViewPager's default implementation, where it looks for swipe gestures--
return super.onInterceptTouchEvent(ev);
}
}
private boolean inNeutralArea(float x, float y) {
//--check if x,y inside non reactive area, return true/false accordingly--
return false;
}
}
Use this MyPager class in layout xml in place of ViewPager.
Don't forget to do to the same in overriding the onTouchEvent, otherwise the ViewPager will still scroll on Android 4.1 and later. Caught me ofguard and took me a while to figure it out.

Categories

Resources