I have made class called ProgressButton that extended RelativeLayout.Now in main xml i added this class:
<com.tazik.progressbutton.ProgressButton
android:id="#+id/pb_button"
android:layout_width="200dp"
android:layout_height="wrap_content"/>
As you can see i added android:layout_width="200dp", now in ProgressButton class i want to get this size to create a button with this size:
public class ProgressButton extends RelativeLayout {
private AppCompatButton button;
public ProgressButton(Context context) {
super(context);
initView();
}
private void initView() {
initButton();
}
private void initButton() {
button = new AppCompatButton(getContext());
LayoutParams button_params = new LayoutParams(????, ViewGroup.LayoutParams.WRAP_CONTENT);
button_params.addRule(RelativeLayout.CENTER_IN_PARENT,RelativeLayout.TRUE);
button.setLayoutParams(button_params);
button.setText("click");
addView(button);
}
I want to create button exactly to size of relativeLayout, so how can i get layout_width in my custom view to set button_params width?
now in ProgressButton class i want to get this size to create a button with this size
As #MikeM. suggested in a comment. It could be as easy as giving that child view a width of MATCH_PARENT. See below...
LayoutParams button_params = new LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
With that in place you don't need to worry about the actual size because MATCH_PARENT will stretch your child view to occupy the whole parent's width...obviosuly respecting margins and paddings.
However, if you do need to know the parent's width, you should query that in onMeasure. I strongly suggest you to stay away from onMeasure whenever possible because it is a bit complex and it might take a lot of your development time.
Either way, in onMeasure you can know what measurements the parent view wants to give to its child views, this is based on the space available to render inside the parent and the layout params specified...
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int widthSpecMode = MeasureSpec.getMode(widthMeasureSpec);
int childWidth = 0;
if(widthSpecMode == MeasureSpec.AT_MOST){
//The parent doesn't want the child to exceed "childWidth", it doesn't care if it smaller than that, just not bigger/wider
childWidth = MeasureSpec.getSize(widthMeasureSpec);
}
else if(widthSpecMode == MeasureSpec.EXACTLY){
//The parent wants the child to be exactly "childWidth"
childWidth = MeasureSpec.getSize(widthMeasureSpec);
}
else {
//The parent doesn't know yet what its children's width will be, probably
//because it's still taking measurements
}
//IMPORTANT!!! set your desired measurements (width and height) or call the base class's onMeasure method. Do one or the other, NOT BOTH
setMeasuredDimension(dimens, dimens);
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
Add a few Log.d calls inside onMeasure for a better understanding of what's happening. Be aware that this method will be called multiple times.
Again, this is an unnecessary overkill for your case scenario. Setting MATCH_PARENT to the button should produce the results you want
I am writing up a custom layout (which extends FrameLayout) that can be zoomed in. All its children are also custom views which would actually get the scale factor from their parent via a getter method and scale accordingly by setting the scaled dimensions like
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
float scaleFactor = ((CustomLayout) getParent()).getCurrentScale();
setMeasuredDimension((int) (getMeasuredWidth() * scaleFactor), (int) (getMeasuredHeight() * scaleFactor));
}
I am using a ScaleGestureDetector to detect the "pinch to zoom" gesture and change the layout's scaleFactor. Then I force a layout on the custom layout by calling requestLayout. Unfortunately this doesn't seem to have any effect on its children. The children's onMeasure & onLayout are never called even though the parent goes through its measure & layout cycle. But, if I directly call requestLayout on one of the children, just that child gets scaled according to the scale factor set in the parent!!
It seems that unless requestLayout is exclusively called on a view, it doesn't actually measure itself again and instead uses some kind of cache. This is evident from the source code for view which says
if (mAttachInfo != null && mAttachInfo.mViewRequestingLayout == null) {
// Only trigger request-during-layout logic if this is the view requesting it,
// not the views in its parent hierarchy
ViewRootImpl viewRoot = getViewRootImpl();
if (viewRoot != null && viewRoot.isInLayout()) {
if (!viewRoot.requestLayoutDuringLayout(this)) {
return;
}
}
mAttachInfo.mViewRequestingLayout = this;
}
How do I force the children also to go measure themselves again on calling requestLayout on their parent?
This will force relayout the view's children (given that view's own width and height does not need to change)
private static void relayoutChildren(View view) {
view.measure(
View.MeasureSpec.makeMeasureSpec(view.getMeasuredWidth(), View.MeasureSpec.EXACTLY),
View.MeasureSpec.makeMeasureSpec(view.getMeasuredHeight(), View.MeasureSpec.EXACTLY));
view.layout(view.getLeft(), view.getTop(), view.getRight(), view.getBottom());
}
I've created a custom view which creates a bitmap and then in the onDraw() method I display an objects data.
Also in the XML file I have made the view horizontally scrollable.
My question is after I've drawn all the data on the canvas from the onDraw() method, how can I increase the view's size to show all the data.
i.e I want the view to scroll just enough until the data has finished and not any more.
I do have the y-coordinate for the last item displayed.
Currently I'm setting the width of the view to 800dp in the XML file, but for some object's it cut's off some of the data.
Thanks
You can override the onMeasure() method to adjust the size of your View:
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int parentViewWidth = MeasureSpec.getSize(widthMeasureSpec);
int parentViewHeight = MeasureSpec.getSize(heightMeasureSpec);
// ... take into account the parent's size as needed ...
super.onMeasure(
MeasureSpec.makeMeasureSpec(newWidth, MeasureSpec.EXACTLY),
MeasureSpec.makeMeasureSpec(newHeight, MeasureSpec.EXACTLY));
}
if I have a layout with fill_parent at height and width, is there a way to get his height and width in onCreate method? if not, when his dimensions are available? I need this because I need to add at runtime some views and I need to know how many views fill in the layout.
You can do that:.
Suppose you have the layout view in onCreate method
layout.post(new Runnable() {
#Override
public void run() {
height= getHeight();
width=getWidth();
//pupulate other views now that you know the parent size
}
}
});
You can use the onSizeChanged method to get the information when it has been calculated, but this may also help to at least get the dimensions of the display.
Display display = ((WindowManager) getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
int width = display.getWidth();
You may find this useful:
when is onSizeChanged() called?
I have a view made up of TableLayout, TableRow and TextView. I want it to look like a grid. I need to get the height and width of this grid. The methods getHeight() and getWidth() always return 0. This happens when I format the grid dynamically and also when I use an XML version.
How to retrieve the dimensions for a view?
Here is my test program I used in Debug to check the results:
import android.app.Activity;
import android.os.Bundle;
import android.widget.TableLayout;
import android.widget.TextView;
public class appwig extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.maindemo); //<- includes the grid called "board"
int vh = 0;
int vw = 0;
//Test-1 used the xml layout (which is displayed on the screen):
TableLayout tl = (TableLayout) findViewById(R.id.board);
tl = (TableLayout) findViewById(R.id.board);
vh = tl.getHeight(); //<- getHeight returned 0, Why?
vw = tl.getWidth(); //<- getWidth returned 0, Why?
//Test-2 used a simple dynamically generated view:
TextView tv = new TextView(this);
tv.setHeight(20);
tv.setWidth(20);
vh = tv.getHeight(); //<- getHeight returned 0, Why?
vw = tv.getWidth(); //<- getWidth returned 0, Why?
} //eof method
} //eof class
I believe the OP is long gone, but in case this answer is able to help future searchers, I thought I'd post a solution that I have found. I have added this code into my onCreate() method:
EDITED: 07/05/11 to include code from comments:
final TextView tv = (TextView)findViewById(R.id.image_test);
ViewTreeObserver vto = tv.getViewTreeObserver();
vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
LayerDrawable ld = (LayerDrawable)tv.getBackground();
ld.setLayerInset(1, 0, tv.getHeight() / 2, 0, 0);
ViewTreeObserver obs = tv.getViewTreeObserver();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
obs.removeOnGlobalLayoutListener(this);
} else {
obs.removeGlobalOnLayoutListener(this);
}
}
});
First I get a final reference to my TextView (to access in the onGlobalLayout() method). Next, I get the ViewTreeObserver from my TextView, and add an OnGlobalLayoutListener, overriding onGLobalLayout (there does not seem to be a superclass method to invoke here...) and adding my code which requires knowing the measurements of the view into this listener. All works as expected for me, so I hope that this is able to help.
I'll just add an alternative solution, override your activity's onWindowFocusChanged method and you will be able to get the values of getHeight(), getWidth() from there.
#Override
public void onWindowFocusChanged (boolean hasFocus) {
// the height will be set at this point
int height = myEverySoTallView.getMeasuredHeight();
}
You are trying to get width and height of an elements, that weren't drawn yet.
If you use debug and stop at some point, you'll see, that your device screen is still empty, that's because your elements weren't drawn yet, so you can't get width and height of something, that doesn't yet exist.
And, I might be wrong, but setWidth() is not always respected, Layout lays out it's children and decides how to measure them (calling child.measure()), so If you set setWidth(), you are not guaranteed to get this width after element will be drawn.
What you need, is to use getMeasuredWidth() (the most recent measure of your View) somewhere after the view was actually drawn.
Look into Activity lifecycle for finding the best moment.
http://developer.android.com/reference/android/app/Activity.html#ActivityLifecycle
I believe a good practice is to use OnGlobalLayoutListener like this:
yourView.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
if (!mMeasured) {
// Here your view is already layed out and measured for the first time
mMeasured = true; // Some optional flag to mark, that we already got the sizes
}
}
});
You can place this code directly in onCreate(), and it will be invoked when views will be laid out.
Use the View's post method like this
post(new Runnable() {
#Override
public void run() {
Log.d(TAG, "width " + MyView.this.getMeasuredWidth());
}
});
I tried to use onGlobalLayout() to do some custom formatting of a TextView, but as #George Bailey noticed, onGlobalLayout() is indeed called twice: once on the initial layout path, and second time after modifying the text.
View.onSizeChanged() works better for me because if I modify the text there, the method is called only once (during the layout pass). This required sub-classing of TextView, but on API Level 11+ View. addOnLayoutChangeListener() can be used to avoid sub-classing.
One more thing, in order to get correct width of the view in View.onSizeChanged(), the layout_width should be set to match_parent, not wrap_content.
Are you trying to get sizes in a constructor, or any other method that is run BEFORE you get the actual picture?
You won't be getting any dimensions before all components are actually measured (since your xml doesn't know about your display size, parents positions and whatever)
Try getting values after onSizeChanged() (though it can be called with zero), or just simply waiting when you'll get an actual image.
As F.X. mentioned, you can use an OnLayoutChangeListener to the view that you want to track itself
view.addOnLayoutChangeListener(new View.OnLayoutChangeListener() {
#Override
public void onLayoutChange(View v, int left, int top, int right, int bottom, int oldLeft, int oldTop, int oldRight, int oldBottom) {
// Make changes
}
});
You can remove the listener in the callback if you only want the initial layout.
I guess this is what you need to look at: use onSizeChanged() of your view. Here is an EXTENDED code snippet on how to use onSizeChanged() to get your layout's or view's height and width dynamically http://syedrakibalhasan.blogspot.com/2011/02/how-to-get-width-and-height-dimensions.html
ViewTreeObserver and onWindowFocusChanged() are not so necessary at all.
If you inflate the TextView as layout and/or put some content in it and set LayoutParams then you can use getMeasuredHeight() and getMeasuredWidth().
BUT you have to be careful with LinearLayouts (maybe also other ViewGroups). The issue there is, that you can get the width and height after onWindowFocusChanged() but if you try to add some views in it, then you can't get that information until everything have been drawn. I was trying to add multiple TextViews to LinearLayouts to mimic a FlowLayout (wrapping style) and so couldn't use Listeners. Once the process is started, it should continue synchronously. So in such case, you might want to keep the width in a variable to use it later, as during adding views to layout, you might need it.
Even though the proposed solution works, it might not be the best solution for every case because based on the documentation for ViewTreeObserver.OnGlobalLayoutListener
Interface definition for a callback to be invoked when the global layout state or the visibility of views within the view tree changes.
which means it gets called many times and not always the view is measured (it has its height and width determined)
An alternative is to use ViewTreeObserver.OnPreDrawListener which gets called only when the view is ready to be drawn and has all of its measurements.
final TextView tv = (TextView)findViewById(R.id.image_test);
ViewTreeObserver vto = tv.getViewTreeObserver();
vto.addOnPreDrawListener(new OnPreDrawListener() {
#Override
public void onPreDraw() {
tv.getViewTreeObserver().removeOnPreDrawListener(this);
// Your view will have valid height and width at this point
tv.getHeight();
tv.getWidth();
}
});
Height and width are zero because view has not been created by the time you are requesting it's height and width . One simplest solution is
view.post(new Runnable() {
#Override
public void run() {
view.getHeight(); //height is ready
view.getWidth(); //width is ready
}
});
This method is good as compared to other methods as it is short and crisp.
You should rather look at View lifecycle: http://developer.android.com/reference/android/view/View.html Generally you should not know width and height for sure until your activity comes to onResume state.
You can use a broadcast that is called in OnResume ()
For example:
int vh = 0;
int vw = 0;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.maindemo); //<- includes the grid called "board"
registerReceiver(new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
TableLayout tl = (TableLayout) findViewById(R.id.board);
tl = (TableLayout) findViewById(R.id.board);
vh = tl.getHeight();
vw = tl.getWidth();
}
}, new IntentFilter("Test"));
}
protected void onResume() {
super.onResume();
Intent it = new Intent("Test");
sendBroadcast(it);
}
You can not get the height of a view in OnCreate (), onStart (), or even in onResume () for the reason that kcoppock responded
Simple Response: This worked for me with no Problem.
It seems the key is to ensure that the View has focus before you getHeight etc. Do this by using the hasFocus() method, then using getHeight() method in that order. Just 3 lines of code required.
ImageButton myImageButton1 =(ImageButton)findViewById(R.id.imageButton1);
myImageButton1.hasFocus();
int myButtonHeight = myImageButton1.getHeight();
Log.d("Button Height: ", ""+myButtonHeight );//Not required
Hope it helps.
Use getMeasuredWidth() and getMeasuredHeight() for your view.
Developer guide: View
CORRECTION:
I found out that the above solution is terrible. Especially when your phone is slow.
And here, I found another solution:
calculate out the px value of the element, including the margins and paddings:
dp to px:
https://stackoverflow.com/a/6327095/1982712
or dimens.xml to px:
https://stackoverflow.com/a/16276351/1982712
sp to px:
https://stackoverflow.com/a/9219417/1982712 (reverse the solution)
or dimens to px:
https://stackoverflow.com/a/16276351/1982712
and that's it.