Develop Reference

Android - how to get height of bottomnavigationview

I create a bottom navigation view. I try to get height of bottom navigation view. Material design says that the height should be 56dp. I don't want to use hard coded value, because I am not sure that this value won't change. How can I get the dimension of the view programmatically like getting status bar's height.
int resourceId =getResources().getIdentifier("status_bar_height","dimen","android");
if (resourceId > 0) {
height = getResources().getDimensionPixelSize(resourceId);
}

You can do this by this in the onCreate method:
bottomNavigationView.post(new Runnable() {
#Override
public void run() {
int height = (int) bottomNavigationView.getMeasuredHeight();
}
});
This will give you height in pixels.
Hope this helps

This is basic code for achieve the height of BottomNavigationView,
int resourceId = getResources().getIdentifier("design_bottom_navigation_height", "dimen", this.getPackageName());
int height = 0;
if (resourceId > 0) {
height = getResources().getDimensionPixelSize(resourceId);
}
//height in pixels
Toast.makeText(this, height + "", Toast.LENGTH_SHORT).show();
// if you want the height in dp
float density = getResources().getDisplayMetrics().density;
float dp = height / density;
Toast.makeText(this, dp + "", Toast.LENGTH_SHORT).show();

Here is another approach. To get the height of BottomNavigationView programatically, I use ViewTreeObserver. This allows me to get the right value of the view after its drawn. Below is the sample code:
BottomNavigationView mBottomNavigation= findViewById(R.id.navigation);
ViewTreeObserver viewTreeObserver = mBottomNavigation.getViewTreeObserver();
if (viewTreeObserver.isAlive()) {
viewTreeObserver.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
int viewHeight = mBottomNavigation.getHeight();
if (viewHeight != 0)
mBottomNavigation.getViewTreeObserver().removeOnGlobalLayoutListener(this);
//viewWidth = mBottomNavigation.getWidth(); //to get view's width
}
});
}
It is very important to remove viewObserver listener once we get the view's height, I am removing viewObserver using:
removeOnGlobalLayoutListener(this)
So that it stops listening to every change in that view.

Custom view's onMeasure: how to get width based on height

The previous version of my question was too wordy. People couldn't understand it, so the following is a complete rewrite. See the edit history if you are interested in the old version.
A RelativeLayout parent sends MeasureSpecs to its child view's onMeasure method in order to see how big the child would like to be. This occurs in several passes.
My custom view
I have a custom view. As the view's content increases, the view's height increases. When the view reaches the maximum height that the parent will allow, the view's width increases for any additional content (as long as wrap_content was selected for the width). Thus, the width of the custom view is directly dependant on what parent says the maximum hight must be.
An (inharmonious) parent child conversation
onMeasure pass 1
The RelativeLayout parent tells my view, "You can be any width up to 900 and any height up to 600. What do you say?"
My view says, "Well, at that height, I can fit everything with a width of 100. So I'll take a width of 100 and a height of 600."
onMeasure pass 2
The RelativeLayout parent tells my view, "You told me last time that you wanted a width of 100, so let's set that as an exact width. Now, based on that width, what kind of height would you like? Anything up to 500 is OK."
"Hey!" my view replies. "If you're only giving me a maximum hight of 500, then 100 is too narrow. I need a width of 200 for that height. But fine, have it your way. I won't break the rules (yet...). I'll take a width of 100 and a height of 500."
Final result
The RelativeLayout parent assigns the view a final size of 100 for the width and 500 for the height. This is of course too narrow for the view and part of the content gets clipped.
"Sigh," thinks my view. "Why won't my parent let me be wider? There is plenty of room. Maybe someone on Stack Overflow can give me some advice."

Update: Modified code to fix some things.
First, let me say that you asked a great question and laid out the problem very well (twice!) Here is my go at a solution:
It seems that there is a lot going on with onMeasure that, on the surface, doesn't make a lot of sense. Since that is the case, we will let onMeasure run as it will and at the end pass judgment on the View's bounds in onLayoutby setting mStickyWidth to the new minimum width we will accept. In onPreDraw, using a ViewTreeObserver.OnPreDrawListener, we will force another layout (requestLayout). From the documentation (emphasis added):
boolean onPreDraw ()
Callback method to be invoked when the view tree is about to be drawn. At this point, all views in the tree have been measured and
given a frame. Clients can use this to adjust their scroll bounds or
even to request a new layout before drawing occurs.
The new minimum width set in onLayout will now be enforced by onMeasure which is now smarter about what is possible.
I have tested this with your example code and it seems to work OK. It will need much more testing. There may be other ways to do this, but that is the gist of the approach.
CustomView.java
import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;
import android.view.ViewTreeObserver;
public class CustomView extends View
implements ViewTreeObserver.OnPreDrawListener {
private int mStickyWidth = STICKY_WIDTH_UNDEFINED;
public CustomView(Context context) {
super(context);
}
public CustomView(Context context, AttributeSet attrs) {
super(context, attrs);
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
logMeasureSpecs(widthMeasureSpec, heightMeasureSpec);
int desiredHeight = 10000; // some value that is too high for the screen
int desiredWidth;
int widthMode = MeasureSpec.getMode(widthMeasureSpec);
int widthSize = MeasureSpec.getSize(widthMeasureSpec);
int heightMode = MeasureSpec.getMode(heightMeasureSpec);
int heightSize = MeasureSpec.getSize(heightMeasureSpec);
int width;
int height;
// Height
if (heightMode == MeasureSpec.EXACTLY) {
height = heightSize;
} else if (heightMode == MeasureSpec.AT_MOST) {
height = Math.min(desiredHeight, heightSize);
} else {
height = desiredHeight;
}
// Width
if (mStickyWidth != STICKY_WIDTH_UNDEFINED) {
// This is the second time through layout and we are trying renogitiate a greater
// width (mStickyWidth) without breaking the contract with the View.
desiredWidth = mStickyWidth;
} else if (height > BREAK_HEIGHT) { // a number between onMeasure's two final height requirements
desiredWidth = ARBITRARY_WIDTH_LESSER; // arbitrary number
} else {
desiredWidth = ARBITRARY_WIDTH_GREATER; // arbitrary number
}
if (widthMode == MeasureSpec.EXACTLY) {
width = widthSize;
} else if (widthMode == MeasureSpec.AT_MOST) {
width = Math.min(desiredWidth, widthSize);
} else {
width = desiredWidth;
}
Log.d(TAG, "setMeasuredDimension(" + width + ", " + height + ")");
setMeasuredDimension(width, height);
}
#Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
int w = right - left;
int h = bottom - top;
super.onLayout(changed, left, top, right, bottom);
// Here we need to determine if the width has been unnecessarily constrained.
// We will try for a re-fit only once. If the sticky width is defined, we have
// already tried to re-fit once, so we are not going to have another go at it since it
// will (probably) have the same result.
if (h <= BREAK_HEIGHT && (w < ARBITRARY_WIDTH_GREATER)
&& (mStickyWidth == STICKY_WIDTH_UNDEFINED)) {
mStickyWidth = ARBITRARY_WIDTH_GREATER;
getViewTreeObserver().addOnPreDrawListener(this);
} else {
mStickyWidth = STICKY_WIDTH_UNDEFINED;
}
Log.d(TAG, ">>>>onLayout: w=" + w + " h=" + h + " mStickyWidth=" + mStickyWidth);
}
#Override
public boolean onPreDraw() {
getViewTreeObserver().removeOnPreDrawListener(this);
if (mStickyWidth == STICKY_WIDTH_UNDEFINED) { // Happy with the selected width.
return true;
}
Log.d(TAG, ">>>>onPreDraw() requesting new layout");
requestLayout();
return false;
}
protected void logMeasureSpecs(int widthMeasureSpec, int heightMeasureSpec) {
int widthMode = MeasureSpec.getMode(widthMeasureSpec);
int widthSize = MeasureSpec.getSize(widthMeasureSpec);
int heightMode = MeasureSpec.getMode(heightMeasureSpec);
int heightSize = MeasureSpec.getSize(heightMeasureSpec);
String measureSpecHeight;
String measureSpecWidth;
if (heightMode == MeasureSpec.EXACTLY) {
measureSpecHeight = "EXACTLY";
} else if (heightMode == MeasureSpec.AT_MOST) {
measureSpecHeight = "AT_MOST";
} else {
measureSpecHeight = "UNSPECIFIED";
}
if (widthMode == MeasureSpec.EXACTLY) {
measureSpecWidth = "EXACTLY";
} else if (widthMode == MeasureSpec.AT_MOST) {
measureSpecWidth = "AT_MOST";
} else {
measureSpecWidth = "UNSPECIFIED";
}
Log.d(TAG, "Width: " + measureSpecWidth + ", " + widthSize + " Height: "
+ measureSpecHeight + ", " + heightSize);
}
private static final String TAG = "CustomView";
private static final int STICKY_WIDTH_UNDEFINED = -1;
private static final int BREAK_HEIGHT = 1950;
private static final int ARBITRARY_WIDTH_LESSER = 200;
private static final int ARBITRARY_WIDTH_GREATER = 800;
}

To make custom layout you need to read and understand this article https://developer.android.com/guide/topics/ui/how-android-draws.html
It isn't difficult to implement behaviour you want. You just need to override onMeasure and onLayout in your custom view.
In onMeasure you will get max possible height of your custom view and call measure() for childs in cycle. After child measurement get desired height from each child and calculate is child fit in current column or not, if not increase custom view wide for new column.
In onLayout you must call layout() for all child views to set them positions within the parent. This positions you have calculated in onMeasure before.

Android center CameraPreview on SurfaceView

I am working on the face detection application for Android (my device is Nexus S with Android 4.1.2). My SurfaceView size is automatically set to 800x480 but my maximal camera resolution is 720x480. I have tried to change the size of SurfaceView in its onLayout() method which worked but then I was missing 80px in the preview. Is it possible to stretch or at least center the CameraPreview?
Thanks

CameraPreview size can be changed using Camera.Parameters.
But I recommend that put the surfaceview on the center of screen.
Here's the code.
I didn't execute the code, but it may works.
// Center the child SurfaceView within the parent.
final int width = r - l;
final int height = b - t;
if (width * previewHeight > height * previewWidth) {
final int surfaceViewWidth = previewWidth * height / previewHeight;
surfaceView.layout((int)((width - surfaceViewWidth)*0.5), 0, (int)((width + surfaceViewWidth)*0.5), height);
} else {
final int surfaceViewHeight = previewHeight * width / previewWidth;
surfaceView.layout(0, (int)((height - surfaceViewHeight)*0.5), width, (int)((height + surfaceViewHeight)*0.5));
}

If anybody else runs into this issue - the way to center the camera preview is with a FrameLayout:
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/surfacecontainer">
<android.view.SurfaceView
android:id="#+id/cameraPreview"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center"/>
</FrameLayout>
More details can be found here.

VideoView to match parent height and keep aspect ratio

I have a VideoView which is set up like this:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/player"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<VideoView
android:id="#+id/video"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_centerInParent="true"
android:layout_centerVertical="true" />
<ProgressBar
android:id="#+id/loader"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true" />
</RelativeLayout>
But the VideoView matches the width of the parent container, and then the height is set according to the aspect ratio of the loaded movie.
I would like to do just the opposite, I want the VideoView to match the height of the parent while keeping the aspect ratio intact, the video will be clipped on the sides.
I managed to stretch the VideoView to fill the parent but then the aspect ratio is not kept.
Another thing is, I'm adding MediaController to the VideoView like this:
MediaController controllers = new MediaController(this) {
#Override
public void hide() {
if (state != State.Hidden) {
this.show();
}
else {
super.hide();
}
}
};
controllers.setAnchorView(videoView);
videoView.setMediaController(controllers);
videoView.setOnPreparedListener(new OnPreparedListener() {
#Override
public void onPrepared(MediaPlayer mediaPlayer) {
controllers.show();
}
});
This works great, and the controllers always stay on, but the height of the controllers is not being taken into account when calculating where to place the video (since it's vertically centered).
My two questions then are:
How do I make the VideoView match the height of the parent yet keep the aspect ratio?
How do I make the VideoView take into account the height of it's controllers?
Thanks.

You should extends from the built-in video view.
Call setVideoSize before video view is shown, you can get video size from thumbnail extracted from video.
So that, when video view's onMeasure is called, both mVideoWidth & mVideoHeight are > 0.
If you want to account the height of controllers, you can do it yourself in the onMeasure method.
Hope will help.
public class MyVideoView extends VideoView {
private int mVideoWidth;
private int mVideoHeight;
public MyVideoView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public MyVideoView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
public MyVideoView(Context context) {
super(context);
}
public void setVideoSize(int width, int height) {
mVideoWidth = width;
mVideoHeight = height;
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// Log.i("###", "onMeasure");
int width = getDefaultSize(mVideoWidth, widthMeasureSpec);
int height = getDefaultSize(mVideoHeight, heightMeasureSpec);
if (mVideoWidth > 0 && mVideoHeight > 0) {
if (mVideoWidth * height > width * mVideoHeight) {
// Log.i("###", "image too tall, correcting");
height = width * mVideoHeight / mVideoWidth;
} else if (mVideoWidth * height < width * mVideoHeight) {
// Log.i("###", "image too wide, correcting");
width = height * mVideoWidth / mVideoHeight;
} else {
// Log.i("###", "aspect ratio is correct: " +
// width+"/"+height+"="+
// mVideoWidth+"/"+mVideoHeight);
}
}
// Log.i("###", "setting size: " + width + 'x' + height);
setMeasuredDimension(width, height);
}
}

I solved this problem with layout. It seems that it worked fine when it was pinned to the corners but it caused the video to skew. To test I changed my relative layout's background to #990000 to see the red poking through.
<?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"
android:id="#+id/relative_parent"
android:background="#000000">
<VideoView
android:layout_alignParentLeft="true"
android:layout_alignParentRight="true"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:focusable="false"
android:focusableInTouchMode="false"
android:id="#+id/videoView" />
</RelativeLayout>

Regarding question 1, I am surprised no one has mentioned the possible use of the MediaPlayer's scaling mode.
https://developer.android.com/reference/android/media/MediaPlayer.html#setVideoScalingMode(int)
It has 2 modes. Both of them always fill the view area. To get it to fill the space while preserving the aspect ratio, thus cropping the long side, you need to switch to the second mode, VIDEO_SCALING_MODE_SCALE_TO_FIT_WITH_CROPPING. That solves one part of the problem. The other part is to change VideoView's measuring behavior, just as some of the other answers demonstrate. This is the way I did it, mostly out of laziness and not familiar with the metadata API's that the others use, you are welcome to use this method or one of the other methods to fix the size of the view. The blanket catch ensures safety when this is called before mMediaPlayer exists, as it may be called many times, and also falls back to old behavior should the field name ever change.
class FixedSizeVideoView : VideoView {
constructor(ctx: Context) : super(ctx)
constructor(ctx: Context, attrs: AttributeSet) : super(ctx, attrs)
// rather than shrink down to fit, stay at the size requested by layout params. Let the scaling mode
// of the media player shine through. If the scaling mode on the media player is set to the one
// with cropping, you can make a player similar to AVLayerVideoGravityResizeAspectFill on iOS
override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
try {
val mpField = VideoView::class.java.getDeclaredField("mMediaPlayer")
mpField.isAccessible = true
val mediaPlayer: MediaPlayer = mpField.get(this) as MediaPlayer
val width = View.getDefaultSize(mediaPlayer.videoWidth, widthMeasureSpec)
val height = View.getDefaultSize(mediaPlayer.videoHeight, heightMeasureSpec)
setMeasuredDimension(width, height)
}
catch (ex: Exception) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec)
}
}
}
So using this class in the layout, you just change the scaling mode on the media Player wherever you have a chance. Such as:
video.setOnPreparedListener { mp: MediaPlayer ->
mp.setVideoScalingMode(MediaPlayer.VIDEO_SCALING_MODE_SCALE_TO_FIT_WITH_CROPPING)
mp.isLooping = true
mp.setScreenOnWhilePlaying(false)
}
video.start()

public class MyVideoView extends VideoView {
private int mVideoWidth;
private int mVideoHeight;
public MyVideoView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public MyVideoView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
public MyVideoView(Context context) {
super(context);
}
#Override
public void setVideoURI(Uri uri) {
MediaMetadataRetriever retriever = new MediaMetadataRetriever();
retriever.setDataSource(this.getContext(), uri);
mVideoWidth = Integer.parseInt(retriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_VIDEO_WIDTH));
mVideoHeight = Integer.parseInt(retriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_VIDEO_HEIGHT));
super.setVideoURI(uri);
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// Log.i("###", "onMeasure");
int width = getDefaultSize(mVideoWidth, widthMeasureSpec);
int height = getDefaultSize(mVideoHeight, heightMeasureSpec);
if (mVideoWidth > 0 && mVideoHeight > 0) {
if (mVideoWidth * height > width * mVideoHeight) {
// Log.i("###", "image too tall, correcting");
height = width * mVideoHeight / mVideoWidth;
} else if (mVideoWidth * height < width * mVideoHeight) {
// Log.i("###", "image too wide, correcting");
width = height * mVideoWidth / mVideoHeight;
} else {
// Log.i("###", "aspect ratio is correct: " +
// width+"/"+height+"="+
// mVideoWidth+"/"+mVideoHeight);
}
}
// Log.i("###", "setting size: " + width + 'x' + height);
setMeasuredDimension(width, height);
}
}

Quick and efficient fix:
No need to create a custom view extending from VideoView. Just set a value big enough to android:layout_width. This will set the widthSpecMode of the video view to View.MeasureSpec.AT_MOST and then the onMeasure() method of VideoView will auto-adjust its width keeping the ratio.
<VideoView
android:id="#+id/video"
android:layout_width="2000dp"
android:layout_height="match_parent" />

Using ConstraintLayout we can achieve this, refer below xml code.
When layout_width and layout_height are 0dp, the size and position of the VideoView are calculated dynamically based on the other constraints. The layout_constraintDimensionRatio attribute indicates that when the app calculates the size of the VideoView, the ratio of the width to the height should be 3:4. This constraint keeps the aspect ratio of the video the same and prevents the view from being stretched too far in either direction (depending on how the device is rotated).
Change layout_constraintDimensionRatio value depending on requirement Portrait/Landscape.
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<VideoView
android:id="#+id/videoView"
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintDimensionRatio="3:4"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>

For the first time a question answered my issue instead of answers!!
My issue was that I had a white space under the video on full screen. I was setting the layout_height to match_parent. The solution was to set it to wrap_content and give the parent a black background. That, and having the VideoView centered vertically in its parent.
I wrote this as a comment but then thought someone might have the same
issue I had, so here it is as an answer also.

I've tried a lot of solutions, while my video was always in 1000*1000 format, so I've created an easy solution for people who know their aspect ratio. First create a VideoView in a RelativeLayout like this:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/video_holder"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:clipToPadding="false">
<VideoView
android:id="#+id/videoView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentBottom="true"
android:layout_alignParentEnd="true"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true" />
</RelativeLayout>
Then before you load the video change the height and with programmatically like this:
int i = videoView.getHeight() > videoView.getWidth() ? videoView.getHeight() : videoView.getWidth();
video_holder.setLayoutParams(new ConstraintLayout.LayoutParams(i, i));
Of course this only works with 1:1 aspect ratio's but you could just use your aspect ratio to change either the height or the width.

Jobbert's answer in Kotlin, in case anyone needs it:
val max = if (videoView.height > videoView.width) videoView.height else videoView.width
videoView.layoutParams = ConstraintLayout.LayoutParams(max, max)

I have been looking for ways to display video in aspect fill in VideoView but after trying many solutions, none of them seems to work.
So I implemented the following approach and it's working for me:
Code:
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// getting screen size
((Activity) getContext()).getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
int width = displayMetrics.widthPixels;
int height = displayMetrics.heightPixels;
double videoSizeRatio = (double) mVideoHeight / mVideoWidth;
double screenSizeRatio = (double) height / width;
if (mVideoWidth > 0 && mVideoHeight > 0) {
if (videoSizeRatio > screenSizeRatio) { // screen is wider than video width
height = (int) (videoSizeRatio * width);
} else if (videoSizeRatio < screenSizeRatio) {
width = (int) (height / videoSizeRatio);
}
}
setMeasuredDimension(width, height);
}
Layout:
<YourCustomizedVideoView
android:id="#+id/videoView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
/>

The best way to do so is
Set width of videoview to max
I was facing the same issue.
I just set the Width to 999px
and Height to match parent
It works.
We get a perfect view like Tik tok or Instagram reels

Just put your VideoView inside the RelativeLayout and set the desired size for that relative layout. like below code,
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="300dp">
<VideoView
android:id="#+id/videoView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_centerInParent="true" />
</RelativeLayout>
It will work.

You just need to put Videoview widget in RelativeLayout (changes in xml file only)
here is reference answer link

Android font size not scaling on tablet [duplicate]

I'm trying to create a method for resizing multi-line text in a TextView such that it fits within the bounds (both the X and Y dimensions) of the TextView.
At present, I have something, but all it does is resize the text such that just the first letter/character of the text fills the dimensions of the TextView (i.e. only the first letter is viewable, and it's huge). I need it to fit all the lines of the text within the bounds of the TextView.
Here is what I have so far:
public static void autoScaleTextViewTextToHeight(TextView tv)
{
final float initSize = tv.getTextSize();
//get the width of the view's back image (unscaled)....
float minViewHeight;
if(tv.getBackground()!=null)
{
minViewHeight = tv.getBackground().getIntrinsicHeight();
}
else
{
minViewHeight = 10f;//some min.
}
final float maxViewHeight = tv.getHeight() - (tv.getPaddingBottom()+tv.getPaddingTop())-12;// -12 just to be sure
final String s = tv.getText().toString();
//System.out.println(""+tv.getPaddingTop()+"/"+tv.getPaddingBottom());
if(minViewHeight >0 && maxViewHeight >2)
{
Rect currentBounds = new Rect();
tv.getPaint().getTextBounds(s, 0, s.length(), currentBounds);
//System.out.println(""+initSize);
//System.out.println(""+maxViewHeight);
//System.out.println(""+(currentBounds.height()));
float resultingSize = 1;
while(currentBounds.height() < maxViewHeight)
{
resultingSize ++;
tv.setTextSize(resultingSize);
tv.getPaint().getTextBounds(s, 0, s.length(), currentBounds);
//System.out.println(""+(currentBounds.height()+tv.getPaddingBottom()+tv.getPaddingTop()));
//System.out.println("Resulting: "+resultingSize);
}
if(currentBounds.height()>=maxViewHeight)
{
//just to be sure, reduce the value
tv.setTextSize(resultingSize-1);
}
}
}
I think the problem is in the use of tv.getPaint().getTextBounds(...). It always returns small numbers for the text bounds... small relative to the tv.getWidth() and tv.getHeight() values... even if the text size is far larger than the width or height of the TextView.

The AutofitTextView library from MavenCentral handles this nicely. The source hosted on Github(1k+ stars) at https://github.com/grantland/android-autofittextview
Add the following to your app/build.gradle
repositories {
mavenCentral()
}
dependencies {
implementation 'me.grantland:autofittextview:0.2.+'
}
Enable any View extending TextView in code:
AutofitHelper.create(textView);
Enable any View extending TextView in XML:
<me.grantland.widget.AutofitLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
>
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:singleLine="true"
/>
</me.grantland.widget.AutofitLayout>
Use the built in Widget in code or XML:
<me.grantland.widget.AutofitTextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:singleLine="true"
/>

New since Android O:
https://developer.android.com/preview/features/autosizing-textview.html
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:autoSizeTextType="uniform"
android:autoSizeMinTextSize="12sp"
android:autoSizeMaxTextSize="100sp"
android:autoSizeStepGranularity="2sp"
/>

I have played with this for quite some time, trying to get my font sizes correct on a wide variety of 7" tablets (kindle fire, Nexus7, and some inexpensive ones in China with low-res screens) and devices.
The approach that finally worked for me is as follows. The "32" is an arbitrary factor that basically gives about 70+ characters across a 7" tablet horizontal line, which is a font size I was looking for. Adjust accordingly.
textView.setTextSize(getFontSize(activity));
public static int getFontSize (Activity activity) {
DisplayMetrics dMetrics = new DisplayMetrics();
activity.getWindowManager().getDefaultDisplay().getMetrics(dMetrics);
// lets try to get them back a font size realtive to the pixel width of the screen
final float WIDE = activity.getResources().getDisplayMetrics().widthPixels;
int valueWide = (int)(WIDE / 32.0f / (dMetrics.scaledDensity));
return valueWide;
}

I was able to answer my own question using the following code (see below), but my solution was very specific to the application. For instance, this will probably only look good and/or work for a TextView sized to approx. 1/2 the screen (with also a 40px top margin and 20px side margins... no bottom margin).
The using this approach though, you can create your own similar implementation. The static method basically just looks at the number of characters and determines a scaling factor to apply to the TextView's text size, and then incrementally increases the text size until the overall height (an estimated height -- using the width of the text, the text height, and the width of the TextView) is just below that of the TextView. The parameters necessary to determine the scaling factor (i.e. the if/else if statements) were set by guess-and-check. You'll likely have to play around with the numbers to make it work for your particular application.
This isn't the most elegant solution, though it was easy to code and it works for me. Does anyone have a better approach?
public static void autoScaleTextViewTextToHeight(final TextView tv, String s)
{
float currentWidth=tv.getPaint().measureText(s);
int scalingFactor = 0;
final int characters = s.length();
//scale based on # of characters in the string
if(characters<5)
{
scalingFactor = 1;
}
else if(characters>=5 && characters<10)
{
scalingFactor = 2;
}
else if(characters>=10 && characters<15)
{
scalingFactor = 3;
}
else if(characters>=15 && characters<20)
{
scalingFactor = 3;
}
else if(characters>=20 && characters<25)
{
scalingFactor = 3;
}
else if(characters>=25 && characters<30)
{
scalingFactor = 3;
}
else if(characters>=30 && characters<35)
{
scalingFactor = 3;
}
else if(characters>=35 && characters<40)
{
scalingFactor = 3;
}
else if(characters>=40 && characters<45)
{
scalingFactor = 3;
}
else if(characters>=45 && characters<50)
{
scalingFactor = 3;
}
else if(characters>=50 && characters<55)
{
scalingFactor = 3;
}
else if(characters>=55 && characters<60)
{
scalingFactor = 3;
}
else if(characters>=60 && characters<65)
{
scalingFactor = 3;
}
else if(characters>=65 && characters<70)
{
scalingFactor = 3;
}
else if(characters>=70 && characters<75)
{
scalingFactor = 3;
}
else if(characters>=75)
{
scalingFactor = 5;
}
//System.out.println(((int)Math.ceil(currentWidth)/tv.getWidth()+scalingFactor));
//the +scalingFactor is important... increase this if nec. later
while((((int)Math.ceil(currentWidth)/tv.getWidth()+scalingFactor)*tv.getTextSize())<tv.getHeight())
{
tv.setTextSize(TypedValue.COMPLEX_UNIT_SP, tv.getTextSize()+0.25f);
currentWidth=tv.getPaint().measureText(s);
//System.out.println(((int)Math.ceil(currentWidth)/tv.getWidth()+scalingFactor));
}
tv.setText(s);
}
Thanks.

I had the same problem and wrote a class that seems to work for me. Basically, I used a static layout to draw the text in a separate canvas and remeasure until I find a font size that fits. You can see the class posted in the topic below. I hope it helps.
Auto Scale TextView Text to Fit within Bounds

Stumbled upon this whilst looking for a solution myself... I'd tried all the other solutions out there that I could see on stack overflow etc but none really worked so I wrote my own.
Basically by wrapping the text view in a custom linear layout I've been able to successfully measure the text properly by ensuring it is measured with a fixed width.
<!-- TextView wrapped in the custom LinearLayout that expects one child TextView -->
<!-- This view should specify the size you would want the text view to be displayed at -->
<com.custom.ResizeView
android:layout_width="fill_parent"
android:layout_height="0dp"
android:layout_margin="10dp"
android:layout_weight="1"
android:orientation="horizontal" >
<TextView
android:id="#+id/CustomTextView"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
</com.custom.ResizeView>
Then the linear layout code
public class ResizeView extends LinearLayout {
public ResizeView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public ResizeView(Context context) {
super(context);
}
#Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
super.onLayout(changed, left, top, right, bottom);
// oldWidth used as a fixed width when measuring the size of the text
// view at different font sizes
final int oldWidth = getMeasuredWidth() - getPaddingBottom() - getPaddingTop();
final int oldHeight = getMeasuredHeight() - getPaddingLeft() - getPaddingRight();
// Assume we only have one child and it is the text view to scale
TextView textView = (TextView) getChildAt(0);
// This is the maximum font size... we iterate down from this
// I've specified the sizes in pixels, but sp can be used, just modify
// the call to setTextSize
float size = getResources().getDimensionPixelSize(R.dimen.solutions_view_max_font_size);
for (int textViewHeight = Integer.MAX_VALUE; textViewHeight > oldHeight; size -= 0.1f) {
textView.setTextSize(TypedValue.COMPLEX_UNIT_PX, size);
// measure the text views size using a fixed width and an
// unspecified height - the unspecified height means measure
// returns the textviews ideal height
textView.measure(MeasureSpec.makeMeasureSpec(oldWidth, MeasureSpec.EXACTLY), MeasureSpec.UNSPECIFIED);
textViewHeight = textView.getMeasuredHeight();
}
}
}
Hope this helps someone.

maybe try setting setHoriztonallyScrolling() to true before taking text measurements so that the textView doesn't try to layout your text on multiple lines

One way would be to specify different sp dimensions for each of the generalized screen sizes. For instance, provide 8sp for small screens, 12sp for normal screens, 16 sp for large and 20 sp for xlarge. Then just have your layouts refer to #dimen text_size or whatever and you can rest assured, as density is taken care of via the sp unit. See the following link for more info on this approach.
http://www.developer.android.com/guide/topics/resources/more-resources.html#Dimension
I must note, however, that supporting more languages means more work during the testing phase, especially if you're interested in keeping text on one line, as some languages have much longer words. In that case, make a dimens.xml file in the values-de-large folder, for example, and tweak the value manually. Hope this helps.

Here is a solution that I created based on some other feedback. This solution allows you to set the size of the text in XML which will be the max size and it will adjust itself to fit the view height.
Size Adjusting TextView
private float findNewTextSize(int width, int height, CharSequence text) {
TextPaint textPaint = new TextPaint(getPaint());
float targetTextSize = textPaint.getTextSize();
int textHeight = getTextHeight(text, textPaint, width, targetTextSize);
while(textHeight > height && targetTextSize > mMinTextSize) {
targetTextSize = Math.max(targetTextSize - 1, mMinTextSize);
textHeight = getTextHeight(text, textPaint, width, targetTextSize);
}
return targetTextSize;
}
private int getTextHeight(CharSequence source, TextPaint paint, int width, float textSize) {
paint.setTextSize(textSize);
StaticLayout layout = new StaticLayout(source, paint, width, Alignment.ALIGN_NORMAL, mSpacingMult, mSpacingAdd, true);
return layout.getHeight();
}

If your only requirement is to have the text automatically split and continue in the next line and the height is not important then just have it like this.
<TextView
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:maxEms="integer"
android:width="integer"/>
This will have your TextView wrap to it's content vertically depending on your maxEms value.

Check if my solution helps you:
Auto Scale TextView Text to Fit within Bounds

I found that this worked well for me. see: https://play.google.com/store/apps/details?id=au.id.rupert.chauffeurs_name_board&hl=en
Source Code at http://www.rupert.id.au/chauffeurs_name_board/verson2.php
http://catchthecows.com/?p=72 and https://github.com/catchthecows/BigTextButton

This is based on mattmook's answer. It worked well on some devices, but not on all. I moved the resizing to the measuring step, made the maximum font size a custom attribute, took margins into account, and extended FrameLayout instead of LineairLayout.
public class ResizeView extends FrameLayout {
protected float max_font_size;
public ResizeView(Context context, AttributeSet attrs) {
super(context, attrs);
TypedArray a = context.getTheme().obtainStyledAttributes(
attrs,
R.styleable.ResizeView,
0, 0);
max_font_size = a.getDimension(R.styleable.ResizeView_maxFontSize, 30.0f);
}
public ResizeView(Context context) {
super(context);
}
#Override
protected void onMeasure(final int widthMeasureSpec, final int heightMeasureSpec) {
// Use the parent's code for the first measure
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
// Assume we only have one child and it is the text view to scale
final TextView textView = (TextView) getChildAt(0);
// Check if the default measure resulted in a fitting textView
LayoutParams childLayout = (LayoutParams) textView.getLayoutParams();
final int textHeightAvailable = getMeasuredHeight() - getPaddingTop() - getPaddingBottom() - childLayout.topMargin - childLayout.bottomMargin;
int textViewHeight = textView.getMeasuredHeight();
if (textViewHeight < textHeightAvailable) {
return;
}
final int textWidthSpec = MeasureSpec.makeMeasureSpec(
MeasureSpec.getSize(widthMeasureSpec) - getPaddingLeft() - getPaddingRight() - childLayout.leftMargin - childLayout.rightMargin,
MeasureSpec.EXACTLY);
final int textHeightSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
for (float size = max_font_size; size >= 1.05f; size-=0.1f) {
textView.setTextSize(TypedValue.COMPLEX_UNIT_PX, size);
textView.measure(textWidthSpec, textHeightSpec);
textViewHeight = textView.getMeasuredHeight();
if (textViewHeight <= textHeightAvailable) {
break;
}
}
}
}
And this in attrs.xml:
<declare-styleable name="ResizeView">
<attr name="maxFontSize" format="reference|dimension"/>
</declare-styleable>
And finally used like this:
<PACKAGE_NAME.ui.ResizeView xmlns:custom="http://schemas.android.com/apk/res/PACKAGE_NAME"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="start|center_vertical"
android:padding="5dp"
custom:maxFontSize="#dimen/normal_text">
<TextView android:id="#+id/tabTitle2"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</PACKAGE_NAME.ui.ResizeView>

Try this...
tv.setText("Give a very large text anc check , this xample is very usefull");
countLine=tv.getLineHeight();
System.out.println("LineCount " + countLine);
if (countLine>=40){
tv.setTextSize(15);
}