We are using fragment compatibility library, and are trying to get width of the fragment, added to FrameLayout. According to fragment lifecycle, until onCreateView is executed, getView().getMeasuredWidth() should return 0. However, we are getting 0 in onStart(), which comes after onCreateView, and therefore, the returned value should not be 0.
This is fragment which width we want to know:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<FrameLayout android:id="#+id/details"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#drawable/carbon_fiber"/>
Why this anomaly is happening? Any help will be appreciated.
Similar to Activities, the views in the view hierarchy haven't been measured at Fragment::onStart(). To get the size of the view, you need to create an OnGlobalLayoutListener and use it in the following manner:
Android get Fragment width
It's just an assumption, but according to Android Developers:
onStart() makes the fragment visible to the user (based on its containing activity being started).
So width and height will be calculated only after your fragment will become visible.
But, maybe, I'm not right.
I ran into the same problem with an Activity. I needed one of my images to maintain a 4:6 ratio. So as simple as I could find for fragments I put the code in its OnStart() for Activities it was the OnWindowFocusChanged()
From researching this it turns out it's because the layout has not actually "drawn" yet. So therefore no components have been measured. There are various other work around but this seemed to me to be the quickest implementations.
In a similar situation I used the post() method of the View class:
getView().post( new Runnable(){
#Override
public void run(){
//do your measurements here
}
});
I think you need to define the android:class with the class of your fragment.
Related
I am currently using an architecture where I have multiple fragments that I swap in the same activity.
I need to be able to use a different background color for one of these fragments BUT I don't want to use the lazy solution that adds one layer of overdraw.
For clarity : I have a window background setted by my theme and on top of it I draw cards & lists. In one of my fragments I need a slightly different window background color.
Is there any way to do that ? I already tried to use a ContextThemeWrapper but it does not seem to work (maybe because the background has already been drawed ?)
Thanks in advance for your help.
Just found it :
It is doable by calling
ColorDrawable cd = new ColorDrawable(getActivity().getResources().getColor(
R.color.your_color));
getActivity().getWindow().setBackgroundDrawable(cd);
during the initialization of your fragment, when it is attached to the activity.
Unfortunately changing a fragment's background at runtime isn't supported. To get this functionality you can wrap your fragment inside of a RelativeLayout or something similar and set the background programmatically on that.
<RelativeLayout
android:id="#+id/fragmentContainer1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#ccc">
<fragment android:name="whatever.fragment.name"
android:id="#+id/frag_1"
android:layout_width="fill_parent"
android:layout_height="fill_parent" />
</RelativeLayout>
Then in your code get by id fragmentContainer1 and do view.setBackgroundColor(YourColorVariable) on it.
Another way may be to get your fragment, find the root view, then set the background on that. fragment.getRootView().setBackgroundColor(Color.WHITE) This depends on your fragment's layout though, so it may or may not work.
On Android 3.0 and above, the android team is driving hard that you should use fragments over activities. And I see this being useful, but I want to be able to handle click events in my app. I'm using a list fragment on the right side of my app, so doing an onclick (or any click listeners) happens in the activity that hosts the fragment. So I had to move from putting a item in XML to using the fragment manager.
In the design documents they show this picture:
http://developer.android.com/training/basics/fragments/fragment-ui.html
What I want is the Fragment A/B tablet UI. However, nowhere in this page does it actually give you an example of doing this - it seems that fragment manager only works with ONE fragment at a time - which is entirely opposite of what the picture portrays. Which makes me think it uses in XML... but then how would I get an onclick? These documents don't make a lot of sense to me. It shows one thing and then says something else. What if I wanted to remove fragment A on the tablet? Add fragment C that doesn't yet exist? Is that even possible if you tried to use Fragment Manager????
I guess I don't get if Fragment manager uses more than 1 fragment, and if it does, how am I supposed to use this to get an item in the picture like the tablet - the left (A) being a listview, and the right (B) being whatever. Without an ID of the fragment I don't how to access it.
Not sure if this is relevant but here is some of my code:
Adds a fragment to the single framelayout I made like in the guide
//Activity
FragLaunch launchPane = new FragLaunch();
// In case this activity was started with special instructions from an Intent,
// pass the Intent's extras to the fragment as arguments
// firstFragment.setArguments(getIntent().getExtras());
// Add the fragment to the 'fragment_container' FrameLayout
getFragmentManager().beginTransaction()
.add(R.id.launch_frag_container, launchPane).commit();
}
Also, in portrait mode of 7" tablets, I want it to use a viewpager that is swipeable. It worked like a charm when I designed it in XML but now that I have to access the listfragment it doesn't work (no way to access since I can't have two fragments)
XML of FragLaunch's content view:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingLeft="16dp"
android:paddingRight="16dp"
android:gravity="center_vertical"
android:orientation="vertical" >
<TextView
android:id="#+id/initial_directions"
style="#style/textScalar.Roboto.Light"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:text="#string/initial_directions"
android:layout_marginBottom="30dp"
tools:context=".Launch" />
</LinearLayout>
I want to have this one appear as Fragment A in the photo:
FragHistory.java/xml for fragment:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<Button
android:id="#+id/spamhistory"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Spam History" />
<ListView
android:id="#android:id/list"
android:layout_width="match_parent"
android:layout_height="0dip"
android:layout_weight="1"
android:drawSelectorOnTop="false" />
</LinearLayout>
Does anyone have any insight on this?
If you want your fragments to be able to communicate then you need to use interfaces, like this.
For onClick events you simply set an onClickListener for the view that you need to receive the onClick event from. Like so:
sampleView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//Your code here
}
});
As for fragment transactions, it says somewhere in there (I can't remember exactly where) that when two fragments are displayed on the screen at once (as with larger screens) that instead of swapping the fragments it simply updates it. All you have to worry about is making the correct calls. So if you want to remove fragment A just call remove(). Or if you want to replace it with fragment C call replace() and pass fragment C in as the parameter.
Can you clarify your question about the ViewPager? What do you mean "have to access it"?
Hope this helps!
EDIT: I apoplogize, I misunderstood your question. Here's kind of a quick run down of how to add more than one fragment to the screen at once.
1. Perform a runtime check to make sure that the device screen is big enough to display more than one fragment.
2. If the screen is big enough, set the content view to use a layout that has a FrameLayout for each fragment that you want to add.
3. After that grab a reference to each fragment that you want to use.
4. Then use the FragmentManager to add a fragment to each layout. Like this:
FirstExampleFragment fragment1 = new FirstExampleFragment();
SecondExampleFragment fragment2 = new SecondExampleFragment();
getSupportFragmentManager().beginTransaction().add(R.id.example_framelayout1, fragment1)
.add(R.id.example_framelayout2, fragment2).commit();
Another great way to allow communication between fragments is to use an event bus, such as the Otto event bus. Otto allows components to publish events and subscribe to events in a decoupled manner.
In your particular case, when a user selects an item in the list, your list fragment can publish an event (which can include the item that has been selected) and your content fragment can subscribe for these events and update its content accordingly when it receives a new event. This all being done without the two fragments being directly coupled and without having to define additional interfaces.
I know this doesn't answer your entire question, but thought it might be useful when it comes to the communications between your fragments....YMMV.
I have an xml layout for a Fragment (android.support.v4.app.Fragment). When this Fragment is added for the first time, the background drawable displays fine. But when this Fragment is replaced with another Fragment, then later replaced back in again (by creating a new instance and using FragmentTransaction.replace()), the background drawable disappears (but not in all cases, see below). Here is the layout xml for the Fragment:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<include layout="#layout/footer_photos" />
<RelativeLayout
android:id="#+id/pageLayout"
android:background="#drawable/body_background2"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_above="#id/footer">
<ImageView
android:id="#+id/page"
android:layout_height="500dp"
android:layout_width="400dp"
android:layout_centerInParent="true"
android:background="#FFF" />
</RelativeLayout>
</RelativeLayout>
The background drawable in question is in the RelativeLayout with the id "pageLayout".
Possible clues:
When I remove the ImageView in there, the background drawable shows up fine.
The other Fragments have similar layout xmls (with the same background drawable), but without ImageViews inside of them, and they work fine.
One of these Fragments has a WebView and buttons inside of it, and this one's background shows up fine.
After replacing the "WebView Fragment" with the Fragment in question, the background shows up fine (!?).
EDIT: The same issue consistently occurs if an image is loaded into the ImageView then a dialog-themed activity is launched on top of it, then finished. My solution below fixes both cases.
Found a better solution than my last one. In onResume() for the Fragment, just need to do:
getView().post(new Runnable() {
#Override
public void run() {
View v = getView();
if (v != null)
v.invalidate();
}
});
It causes a flicker, but at least it seems to work consistently.
i had a similar problem. With a relativelayout, there was an imageView and a textView.
I resolved with a call to bringToFront method:
myImageView.bringToFront();
Hope this helped.
Okay, I fixed this issue while trying to fix another issue. The issue was solved by calling setLayoutParams() on the page ImageView (with whatever layout params). This caused the background of the pageLayout RelativeLayout to show up again. The cause of the issue remains unknown...
The fragments are replaced , along with their background, which means that
when a fragment A is replaced by fragment B, the background changes to the background of fragment B.
If you don't give any background to fragment B, then you can see fragment B over fragment A.
I have activity and a lot of widgets on it, some of them have animations and because of the animations some of the widgets are moving (translating) one over another. For example the text view is moving over some buttons . . .
Now the thing is I want the buttons to be always on the front. And when the textview is moving I want to move behind the buttons.
I can not achieve this I tried everything I know, and "bringToFront()" definitelly doesn't work.
note I do not want to control the z-order by the order of placing element to layout cause I simply can't :), the layout is complex and I can not place all the buttons at the begging of the layout
You can call bringToFront() on the view you want to get in the front
This is an example:
yourView.bringToFront();
With this code in xml
android:translationZ="90dp"
I've been looking through stack overflow to find a good answer and when i couldn't find one i went looking through the docs.
no one seems to have stumbled on this simple answer yet:
ViewCompat.setTranslationZ(view, translationZ);
default translation z is 0.0
An even simpler solution is to edit the XML of the activity. Use
android:translationZ=""
bringToFront() is the right way, but, NOTE that you must call bringToFront() and invalidate() method on highest-level view (under your root view), for e.g.:
Your view's hierarchy is:
-RelativeLayout
|--LinearLayout1
|------Button1
|------Button2
|------Button3
|--ImageView
|--LinearLayout2
|------Button4
|------Button5
|------Button6
So, when you animate back your buttons (1->6), your buttons will under (below) the ImageView. To bring it over (above) the ImageView you must call bringToFront() and invalidate() method on your LinearLayouts. Then it will work :)
**NOTE: Remember to set android:clipChildren="false" for your root layout or animate-view's gradparent_layout. Let's take a look at my real code:
.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:hw="http://schemas.android.com/apk/res-auto"
android:id="#+id/layout_parent"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/common_theme_color"
android:orientation="vertical" >
<com.binh.helloworld.customviews.HWActionBar
android:id="#+id/action_bar"
android:layout_width="match_parent"
android:layout_height="#dimen/dimen_actionbar_height"
android:layout_alignParentTop="true"
hw:titleText="#string/app_name" >
</com.binh.helloworld.customviews.HWActionBar>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="#id/action_bar"
android:clipChildren="false" >
<LinearLayout
android:id="#+id/layout_top"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:gravity="center_horizontal"
android:orientation="horizontal" >
</LinearLayout>
<ImageView
android:id="#+id/imgv_main"
android:layout_width="#dimen/common_imgv_height"
android:layout_height="#dimen/common_imgv_height"
android:layout_centerInParent="true"
android:contentDescription="#string/app_name"
android:src="#drawable/ic_launcher" />
<LinearLayout
android:id="#+id/layout_bottom"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:gravity="center_horizontal"
android:orientation="horizontal" >
</LinearLayout>
</RelativeLayout>
</RelativeLayout>
Some code in .java
private LinearLayout layoutTop, layoutBottom;
...
layoutTop = (LinearLayout) rootView.findViewById(R.id.layout_top);
layoutBottom = (LinearLayout) rootView.findViewById(R.id.layout_bottom);
...
//when animate back
//dragedView is my layoutTop's child view (i added programmatically) (like buttons in above example)
dragedView.setVisibility(View.GONE);
layoutTop.bringToFront();
layoutTop.invalidate();
dragedView.startAnimation(animation); // TranslateAnimation
dragedView.setVisibility(View.VISIBLE);
GLuck!
Try FrameLayout, it gives you the possibility to put views one above another. You can create two LinearLayouts: one with the background views, and one with foreground views, and combine them using the FrameLayout. Hope this helps.
If you are using ConstraintLayout, just put the element after the other elements to make it on front than the others
i have faced the same problem.
the following solution have worked for me.
FrameLayout glFrame=(FrameLayout) findViewById(R.id.animatedView);
glFrame.addView(yourView);
glFrame.bringToFront();
glFrame.invalidate();
2nd solution is by using xml adding this attribute to the view xml
android:translationZ=""
You can try to use the bringChildToFront, you can check if this documentation is helpful in the Android Developers page.
There can be another way which saves the day. Just init a new Dialog with desired layout and just show it. I need it for showing a loadingView over a DialogFragment and this was the only way I succeed.
Dialog topDialog = new Dialog(this, android.R.style.Theme_Translucent_NoTitleBar);
topDialog.setContentView(R.layout.dialog_top);
topDialog.show();
bringToFront() might not work in some cases like mine. But content of dialog_top layout must override anything on the ui layer. But anyway, this is an ugly workaround.
You can use BindingAdapter like this:
#BindingAdapter("bringToFront")
public static void bringToFront(View view, Boolean flag) {
if (flag) {
view.bringToFront();
}
}
<ImageView
...
app:bringToFront="#{true}"/>
The order of the overlapping views really depends of 4 things:
The attribute android:elevation which is measured in dp/sp
The attribute android:translationZ which is also measured in dp/sp.
In Constraint Layout, the order in which you put the views in your Component Tree is also the order to be shown.
The programmatically order that you set through methods like view.bringToFront() in your kotlin/java code.
The numerals 1 and 2 compite with each other and take preference over the points 3 and 4: if you set elevation="4dp" for View 1 and translationZ="2dp" for View 2, View 1 will always be on top regardless of the numerals 3 and 4.
Thanks to Stack user over this explanation, I've got this working even on Android 4.1.1
((View)myView.getParent()).requestLayout();
myView.bringToFront();
On my dynamic use, for example, I did
public void onMyClick(View v)
{
((View)v.getParent()).requestLayout();
v.bringToFront();
}
And Bamm !
You can use elevation attribute if your minimum api level is 21. And you can reorder view to the bottom of other views to bring it to front. But if elevation of other views is higher, they will be on top of your view.
If you are using a LinearLayout you should call myView.bringToFront() and after you should call parentView.requestLayout() and parentView.invalidate() to force the parent to redraw with the new child order.
Arrange them in the order you wants to show. Suppose, you wanna show view 1 on top of view 2. Then write view 2 code then write view 1 code. If you cant does this ordering, then call bringToFront() to the root view of the layout you wants to bring in front.
Try to use app:srcCompat instead of android:src
You need to use framelayout. And the better way to do this is to make the view invisible when thay are not require. Also you need to set the position for each and every view,So that they will move according to there corresponding position
You can set visibility to false of other views.
view1.setVisibility(View.GONE);
view2.setVisibility(View.GONE);
...
or
view1.setVisibility(View.INVISIBLE);
view2.setVisibility(View.INVISIBLE);
...
and set
viewN.setVisibility(View.VISIBLE);
I am using the method setKeepScreenOn(true) and haven't been able to figure out how to call this in relation to the current Activity (which has a content view set). I've been able to get it to work by calling it on one of my buttons which is always present in the view, but this feels wrong - and I'm sure there must be a way to get around this. I tried referencing the current focus like this:
getCurrentFocus().setKeepScreenOn(true);
but that threw a NullPointerException. Maybe there was no current focus.
So, can anyone tell me how I can reference the view class which I am working inside? Thanks :)
Try this answer:
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
getWindow is a method defined for activities, and won't require you to find a View first.
As Hawk said but poorly explained.
You can also use FLAG_KEEP_SCREEN_ON in your XML layout file.
Note the android:keepScreenOn="true"
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:keepScreenOn="true"
android:orientation="vertical" >
<!-- whatever is in your layout -->
</LinearLayout>
I've now written all the choices for keeping the screen on up into a blog post:
http://blog.blundellapps.com/tut-keep-screen-onawake-3-possible-ways/
Set android:keepScreenOn in XML
If you are doing it on a class extends View. You can simple:
this.setKeepScreenOn(true);
According to Google Docs for android Developers you've two ways to do this :
First way :
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
}
Second way is to add in your xml file layout this attribute:
android:keepScreenOn="true"