I want to create a custom layout to reduce redundancy in the code. Currently every layoutfile has about 30 Lines of code which are identical.
My goal was to create a custom layout/view which can hold in itself children.
<BaseLayout xmlns:...>
<!-- Normal Content -->
<Button />
<Label />
</BaseLayout>
While the above xml holds most of the content, the BaseLayout is in itself an xml containing other views and functionality:
<FrameLayout xmlns:...>
<LinearLayout><!-- contains the Header--></LinearLayout>
<LinearLayout><!-- INDIVIDUAL CONTENT HERE--></LinearLayout>
<FrameLayout><!-- contains the loading screen overlay --></FrameLayout>
</FrameLayout>
So all children from the above xml should be inserted into second linear-layout. I have already succeeded into doing so. But am confronted with layout problems (match parents does not match parents and only wraps)
My approach was extending the LinearLayout with following logic:
/**
* extracting all children and adding them to the inflated base-layout
*/
#Override
protected void onFinishInflate() {
super.onFinishInflate();
View view = LayoutInflater.from(getContext()).inflate(R.layout.base_layout, null);
LinearLayout linearLayout = (LinearLayout) view.findViewById(R.id.base_layout_children);
while(0 < getChildCount())
{
View child = getChildAt(0);
LinearLayout.MarginLayoutParams layoutParams = (MarginLayoutParams) child.getLayoutParams();
removeViewAt(0);
linearLayout.addView(child, layoutParams);
}
this.addView(view);
}
Is there a better, cleaner approach to capsule the xml and reuse a basis layout? How do I fix the match_parent issue?
While writing this post and thinking hard how to explain best, the solution for the match_parent issue became clear. Though the question remains if there is a better approach for the whole problem.
//Solution:
this.addView(view, new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));
//wrong:
this.addView(view);
Suppose you have two layout files. common_views.xml and layout_main.xml. You can include content of one layout file into another like this.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<include
android:id="#+id/common"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
layout="#layout/common_views" />
<WebView
android:id="#+id/webView"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_below="#+id/common"
>
</WebView>
</RelativeLayout>
I'm doing this in Xamarin, so there will be slight deviations in the casing and names of methods.
I have a RelativeLayout that has ads and is placed at the bottom. Unfortunately, the ads block part of the playable map, so I'm attempting to move it to the top when the player moves near the bottom. I initialize the banner with the following code:
_banner = new RelativeLayout(this);
_lp = new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.MatchParent, ViewGroup.LayoutParams.WrapContent);
_lp.AddRule(LayoutRules.AlignParentBottom);
_lp.AddRule(LayoutRules.AlignParentLeft);
AddContentView(_banner, _lp);
I'm now attempting to move it to the top, but am failing. I've tried removing and re-adding it, but that does nothing.
var lp = new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.MatchParent, ViewGroup.LayoutParams.WrapContent);
((FrameLayout)(_banner.Parent)).RemoveView(_banner);
lp.AddRule(LayoutRules.AlignParentTop);
lp.AddRule(LayoutRules.AlignParentLeft);
AddContentView(_banner, lp);
I've also tried setting the LayoutParameters, but that throws an exception. What am I doing wrong?
Thank you.
-Nick
From your code I gather you are nesting a RelativeLayout (contains the ad) inside a FrameLayout. Your RelativeLayout only matches your parent in width, not height.
As such the RelativeLayout doesn't have the same size as your FrameLayout.
Your ad is thus touching both top and bottom of the RelativeLayout. And that RelativeLayout is always aligned to the top of the FrameLayout.
To solve this you have three options:
Make the RelativeLayout match the entire height of the FrameLayout and position your ad within that RelativeLayout.
Change the FrameLayout into a RelativeLayout, that way your alignParentBottom parameter will start working.
Use a 'layout_gravity' parameter on the RelativeLayout to tell the FrameLayout you want this View sent to the bottom.
Effectively your code is doing:
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<RelativeLayout
android:alignParentBottom="true"
android:background="#FF0000"
android:layout_width="match_parent"
android:layout_height="240dp"
/>
</FrameLayout>
But for stuff to work you need to use android:layout_gravity which is a FrameLayout.LayoutParameter.
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<RelativeLayout
android:layout_gravity="bottom"
android:background="#FF0000"
android:layout_width="match_parent"
android:layout_height="240dp"
/>
</FrameLayout>
Just paste the two pieces in a layout.xml and use the Android Designer to view the difference.
I have a ScrollView with a RelativeLayout inside it.
<ScrollView
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:fillViewport="true">
<RelativeLayout
android:id="#+id/toWrap"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#color/background_color">
I want to make this RelativeLayout not fill its parent, but fill the display.
I want that because when I open the keyboard, the layout gets ugly.
I've tried to create a ExpandableRelativeLayout subclass with onDraw like this:
#Override
protected void onDraw(Canvas canvas)
{
DisplayMetrics metrics = Resources.getSystem().getDisplayMetrics();
setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, (int)(metrics.heightPixels * metrics.density)));
super.onDraw(canvas);
}
But I constantly received this error:
E/AndroidRuntime(15331): java.lang.ClassCastException: android.widget.RelativeLayout$LayoutParams cannot be cast to android.widget.FrameLayout$LayoutParams`
How do I do that?
Thanks.
I think you should use RelativeLayout.LayoutParams instead of layoutparams. That what I always do and didnot have any errors. Also if you are using ecllipse and you altered the xml and this error occured after that then you should close ecllipse and start again. This is a bug in ecllipse where at some point your R.java stops generating and classcastexception occurs.
What I have to implement in order to limit the max size of a FrameLayout or the View inside it?
I am using a FrameLayout for my Android app:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<FrameLayout
android:id="#+id/dog_holder"
android:layout_width="match_parent"
android:layout_height="match_parent">
</FrameLayout>
</LinearLayout>
I have added a View to it:
FrameLayout frame = (FrameLayout) findViewById(R.id.dog_holder);
dog = new DogView(this);
frame.addView(dog);
(DogView extends View)
I am initializing the View with a bitmap:
my_dog = BitmapFactory.decodeResource(getResources(), R.drawable.dog);
I want to move around the picture (I have implemented the touch controls) but not to be able to move outside it. Good example is a picture gallery app: while a picture is zoomed you can go around it but on the borders there is bouncy effect which doesn't allow to go into the dark side.
What I have to implement to stop me when I try to go outside the dimension of the bitmap?
Okay, so I've done some looking around and I see how you are SUPPOSED to do it, but for me, it is just not working.
I need to be able to set the alpha of a RelativeLayout both in XML and in code. For my XML, I have the following
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/player_controls"
android:layout_height="match_parent"
android:layout_width="match_parent"
android:alpha="0.0">
<RelativeLayout
android:layout_height="match_parent"
android:layout_width="match_parent"
android:id="#+id/player_controls_touch_me"
>
</RelativeLayout>
</RelativeLayout>
I get the error: no resource identifier found for attribute 'alpha' in package 'android'
Also, based on the Android documentation, I should be able to call setAlpha(double) on any View object, but when I try to make that call on a RelativeLayout it tells me that this method is not defined for this object.
Why am I not able to control the alpha transparency for a RelativeLayout object in Android? Am i missing something? Thanks!
Update
Although using the visibility property works, it prevents me from be able to click on the ViewGroup. This is important for me because I am utilizing the OnTouchListener of the ViewGroup.
What I am trying to do is to have a layer with media controls, initially hidden. when the user taps anywere on the screen, I want the controls to fade in and when they tap the screen again I want the controls to fade out. I have this part already working. I am using a viewgroup that sits over-top my entire application with an OnTouchListener attached that can determine if it has or hasn't been touched. My problem is that after the animation runs to fade out the controls, they re-appear. If I use #Hydrangea suggestion, I can have it fade out and immediately made invisible. This gives me the desired effect, but then the ViewGroup is unclickable and the user cannot get the controls to come back (or go away, depending on what we decide to do first).
I hope this makes sense.
You'll want to use a alpha animation to fade things in and out. This will maintain your touch events for your layouts. Here's an example
public class Main extends Activity {
/** Called when the activity is first created. */
private boolean mShowing = false;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
findViewById(R.id.textview).setOnClickListener(new OnClickListener(){
#Override
public void onClick(View arg0) {
if(mShowing){
Animation animation = new AlphaAnimation(1.0f, 0.0f);
animation.setFillAfter(true);
arg0.startAnimation(animation);
} else {
Animation animation = new AlphaAnimation(0.0f, 1.0f);
animation.setFillAfter(true);
arg0.startAnimation(animation);
}
mShowing = !mShowing;
}
});
}
}
Here's the accompanying xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TextView
android:id="#+id/textview"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="#string/hello"
android:clickable="true"
/>
</LinearLayout>
Unless you need levels of alpha between 0 and 1, I'd suggest, if you truly want to make this item invisible, to use setVisibility();
android:visibility="invisible"
I checked out the android:alpha line, and my ide doesn't find it either. I can't guess why, though... the documentation seems pretty clear.
The alpha property is new in Android 3.0, and it's not the most efficient way to hide a view. Use View.setVisibility() or android:visibility to achieve what you want.
You can set alpha by setting the (background) color i guess. Color values can be in the format of #aarrggbb (alpha, red, green, blue).
You can add to the right answer the following option:
animation.setDuration(xxx);
To each animation instance. In this way your animation will look better.
Based on your discription, you should be able to create a view that contains only the relative layout and have the onClickListener set to it. This way you can set the visibility of the relative layout to invisible, but still register a click.
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/clickable_layout"
android:layout_height="match_parent"
android:layout_width="match_parent" >
<RelativeLayout
android:id="#+id/player_controls"
android:layout_height="match_parent"
android:layout_width="match_parent" >
<RelativeLayout
android:layout_height="match_parent"
android:layout_width="match_parent"
android:id="#+id/player_controls_touch_me"
>
</RelativeLayout>
</RelativeLayout>
</FrameLayout>
Use onTouchEvent in Activity, and then you could get touch event to control to your RelativeLayout even if it is "invisible".