I've read many other SO answers but nothing seems to be what I want. What I want is a ViewPager inside a ScrollView with the heights of each page being appropriate for the content. Some of the more accepted answers on SO seem to have to take the max height of the children in the ViewPager but that leads for empty space.
WrapContentViewPager
public class WrapContentViewPager extends ViewPager {
public WrapContentViewPager(Context context) {
super(context);
}
public WrapContentViewPager(Context context, AttributeSet attrs) {
super(context, attrs);
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int height = 0;
View view = null;
for(int i = 0; i < getChildCount(); i++) {
view = getChildAt(i);
view.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
int h = view.getMeasuredHeight();
if(h > height) height = h;
}
if (height != 0) {
heightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);
}
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
setMeasuredDimension(getMeasuredWidth(), measureHeight(heightMeasureSpec, view));
}
/**
* Determines the height of this view
*
* #param measureSpec A measureSpec packed into an int
* #param view the base view with already measured height
*
* #return The height of the view, honoring constraints from measureSpec
*/
private int measureHeight(int measureSpec, View view) {
int result = 0;
int specMode = MeasureSpec.getMode(measureSpec);
int specSize = MeasureSpec.getSize(measureSpec);
if (specMode == MeasureSpec.EXACTLY) {
result = specSize;
} else {
// set the height from the base view if available
if (view != null) {
result = view.getMeasuredHeight();
}
if (specMode == MeasureSpec.AT_MOST) {
result = Math.min(result, specSize);
}
}
return result;
}
}
The reason why this doesn't work is because if I go to the third page, which has a large height with 32 items in the list, then go back to the second page with only 3 items, there is a lot of empty space in the second page since it took the height of the third page as max.
I've tried WCViewPager library on GitHub at https://github.com/rnevet/WCViewPager and it doesn't work for me as well.
Could someone guide me to a correct solution? I am using a ViewPager with just PagerAdapter, not FragmentPagerAdapter by the way.
UPDATE
I figured out a better way to solve it.
`public class WrapContentViewPager extends ViewPager {
public WrapContentViewPager(Context context) {
super(context);
}
public WrapContentViewPager(Context context, AttributeSet attrs) {
super(context, attrs);
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int mode = MeasureSpec.getMode(heightMeasureSpec);
// Unspecified means that the ViewPager is in a ScrollView WRAP_CONTENT.
// At Most means that the ViewPager is not in a ScrollView WRAP_CONTENT.
if (mode == MeasureSpec.UNSPECIFIED || mode == MeasureSpec.AT_MOST) {
// super has to be called in the beginning so the child views can be initialized.
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
int position = getCurrentItem();
View child = this.findViewWithTag("view"+position);
child.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
int height = child.getMeasuredHeight();
heightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);
}
// super has to be called again so the new specs are treated as exact measurements
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}`
and in my PagerAdapter I changed the method instantiateItem
#Override
public #NonNull Object instantiateItem(#NonNull ViewGroup view, int position) {
View layout = inflater.inflate(R.layout.layout, view, false);
layout.setTag("view" + position);
}
This solution remeasures the height at the current page every time it is moved. getChildAt(getCurrentItem()) gives different results so it's not reliable.
I have a ViewGroup that contain one child(ImageButton).
I want the viewGroup has exact size of its child.
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int desiredWidth = getChildAt(0).getMeasuredWidth();
int desiredHeight = getChildAt(0).getMeasuredHeight();
int width = resolveSize(desiredWidth,widthMeasureSpec);
int height = resolveSize(desiredHeight,heightMeasureSpec);
setMeasuredDimension(width,height);
}
I get children size (ImageButton) by getMeasuredWidth() and getMeasuredWidth() but they return 0 value.
You did not measure the child view, hence its width and height are not set (yet).
Either call super.onMeasure(...) in your method to let your super class measure the child, or do it yourself by calling child.measure(widthMeasureSpec, heightMeasureSpec).
I have the following classes:
public class MyGridView extends ViewGroup {
...
#Override
public void onSizeChanged(int xNew, int yNew, int xOld, int yOld) {
super.onSizeChanged(xNew, yNew, xOld, yOld);
// do calculations for drawing bounds of child views
}
#Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
View child;
Rect rect;
for (int i=0; i < getChildCount(); i++) {
child = getChildAt(i);
rect = getBoundsAtChildIndex(i)
child.layout(rect.left, rect.top, rect.right, rect.bottom);
}
}
...
}
AND
public class MyAdapter {
public void setMyGridView(MyGridView myGridView) {
// add a single TextView to my grid view
textView = createTextView(context);
addTextViewToGrid(textView);
container.add(textView);
}
private TextView createTextView(Context context) {
TextView textView = new TextView(context);
textView.setText("1");
textView.setTextColor(0xffffffff);
textView.setTextSize(TypedValue.COMPLEX_UNIT_SP, 12f);
textView.setTypeface(typeface);
textView.setGravity(Gravity.CENTER | Gravity.FILL);
// textView.setGravity(Gravity.RIGHT); // other tries to see gravity
// textView.setGravity(Gravity.FILL);
return textView;
}
private void addTextViewToGrid(TextView textView) {
myGridViewPtr.addView(textView, ViewGroup.LayoutParams.MATCH_PARENT,
ViewGroup.LayoutParams.MATCH_PARENT);
}
...
}
I have created a custom grid view and adapter, where its children draw to the screen to the correct size and location. However, their gravity, set in the createTextView() is not observed.
I can set a background image to the textView and see it fill its space in the grid.
In contrast, the text in textView always draws in its top left corner, and it always stays at the text size I set it at 12sp, rather than scale to fit using Gravity.FILL.
Preferably, the text would scale to fit and center within the textview.
EDIT
I have added the following method for onMeasure() in ViewGroup:
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
int width = getMeasuredWidth();
int height = getMeasuredHeight();
doUpdateOnSizeChanged(width, height);
for (int i = 0; i < getChildCount(); i++)
getChildAt(i).measure((int) viewDim.x, (int) viewDim.y);
setMeasuredDimension(width, height);
}
The children are supposed to be the same height, width as each other. The android example code for ViewGroup is more sophisticated than I require. For instance, I am not getting the max of all children width, height.
For my onMeasure(), the child width, height in ViewDim is width, height integers that are computed in doUpdateOnSizeChanged to be less than getMeasuredWidth, getMeasuredHeight.
The result is now text aligns in the bottom-left corner of the TextView.
onMeasure needed minor corrections, basically needing to rely on MeasureSpec:
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int width, height;
int cWidth1, cHeight1;
width = MeasureSpec.getSize(widthMeasureSpec);
height = MeasureSpec.getSize(heightMeasureSpec);
doUpdateOnSizeChanged(width, height);
cWidth1 = (int)viewDim.x; cHeight1 = (int)viewDim.y;
measureChildren(MeasureSpec.makeMeasureSpec(cWidth1, MeasureSpec.EXACTLY),
MeasureSpec.makeMeasureSpec(cHeight1, MeasureSpec.EXACTLY));
setMeasuredDimension(width, height);
}
Using the new GridLayoutManager: https://developer.android.com/reference/android/support/v7/widget/GridLayoutManager.html
It takes an explicit span count, so the problem now becomes: how do you know how many "spans" fit per row? This is a grid, after all. There should be as many spans as the RecyclerView can fit, based on measured width.
Using the old GridView, you would just set the "columnWidth" property and it would automatically detect how many columns fit. This is basically what I want to replicate for the RecyclerView:
add OnLayoutChangeListener on the RecyclerView
in this callback, inflate a single 'grid item' and measure it
spanCount = recyclerViewWidth / singleItemWidth;
This seems like pretty common behavior, so is there a simpler way that I'm not seeing?
Personaly I don't like to subclass RecyclerView for this, because for me it seems that there is GridLayoutManager's responsibility to detect span count. So after some android source code digging for RecyclerView and GridLayoutManager I wrote my own class extended GridLayoutManager that do the job:
public class GridAutofitLayoutManager extends GridLayoutManager
{
private int columnWidth;
private boolean isColumnWidthChanged = true;
private int lastWidth;
private int lastHeight;
public GridAutofitLayoutManager(#NonNull final Context context, final int columnWidth) {
/* Initially set spanCount to 1, will be changed automatically later. */
super(context, 1);
setColumnWidth(checkedColumnWidth(context, columnWidth));
}
public GridAutofitLayoutManager(
#NonNull final Context context,
final int columnWidth,
final int orientation,
final boolean reverseLayout) {
/* Initially set spanCount to 1, will be changed automatically later. */
super(context, 1, orientation, reverseLayout);
setColumnWidth(checkedColumnWidth(context, columnWidth));
}
private int checkedColumnWidth(#NonNull final Context context, final int columnWidth) {
if (columnWidth <= 0) {
/* Set default columnWidth value (48dp here). It is better to move this constant
to static constant on top, but we need context to convert it to dp, so can't really
do so. */
columnWidth = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 48,
context.getResources().getDisplayMetrics());
}
return columnWidth;
}
public void setColumnWidth(final int newColumnWidth) {
if (newColumnWidth > 0 && newColumnWidth != columnWidth) {
columnWidth = newColumnWidth;
isColumnWidthChanged = true;
}
}
#Override
public void onLayoutChildren(#NonNull final RecyclerView.Recycler recycler, #NonNull final RecyclerView.State state) {
final int width = getWidth();
final int height = getHeight();
if (columnWidth > 0 && width > 0 && height > 0 && (isColumnWidthChanged || lastWidth != width || lastHeight != height)) {
final int totalSpace;
if (getOrientation() == VERTICAL) {
totalSpace = width - getPaddingRight() - getPaddingLeft();
} else {
totalSpace = height - getPaddingTop() - getPaddingBottom();
}
final int spanCount = Math.max(1, totalSpace / columnWidth);
setSpanCount(spanCount);
isColumnWidthChanged = false;
}
lastWidth = width;
lastHeight = height;
super.onLayoutChildren(recycler, state);
}
}
I don't actually remember why I choosed to set span count in onLayoutChildren, I wrote this class some time ago. But the point is we need to do so after view get measured. so we can get it's height and width.
EDIT 1: Fix error in code caused to incorrectly setting span count. Thanks user #Elyees Abouda for reporting and suggesting solution.
EDIT 2: Some small refactoring and fix edge case with manual orientation changes handling. Thanks user #tatarize for reporting and suggesting solution.
I accomplished this using a ViewTreeObserver to get the width of the RecylcerView once rendered and then getting the fixed dimensions of my CardView from resources and then setting the span count after doing my calculations. It is only really applicable if the items you are displaying are of a fixed width. This helped me automatically populate the grid regardless of screen size or orientation.
mRecyclerView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
mRecyclerView.getViewTreeObserver().removeOnGlobalLayoutListener(this);
int viewWidth = mRecyclerView.getMeasuredWidth();
float cardViewWidth = getActivity().getResources().getDimension(R.dimen.cardview_layout_width);
int newSpanCount = (int) Math.floor(viewWidth / cardViewWidth);
mLayoutManager.setSpanCount(newSpanCount);
mLayoutManager.requestLayout();
}
});
Well, this is what I used, fairly basic, but gets the job done for me. This code basically gets the screen width in dips and then divides by 300 (or whatever width you're using for your adapter's layout). So smaller phones with 300-500 dip width only display one column, tablets 2-3 columns etc. Simple, fuss free and without downside, as far as I can see.
Display display = getActivity().getWindowManager().getDefaultDisplay();
DisplayMetrics outMetrics = new DisplayMetrics();
display.getMetrics(outMetrics);
float density = getResources().getDisplayMetrics().density;
float dpWidth = outMetrics.widthPixels / density;
int columns = Math.round(dpWidth/300);
mLayoutManager = new GridLayoutManager(getActivity(),columns);
mRecyclerView.setLayoutManager(mLayoutManager);
I extended the RecyclerView and overrode the onMeasure method.
I set an item width(member variable) as early as I can,with a default of 1. This also updates on configuration changed. This will now have as many rows as can fit in portrait,landscape,phone/tablet etc.
#Override
protected void onMeasure(int widthSpec, int heightSpec) {
super.onMeasure(widthSpec, heightSpec);
int width = MeasureSpec.getSize(widthSpec);
if(width != 0){
int spans = width / mItemWidth;
if(spans > 0){
mLayoutManager.setSpanCount(spans);
}
}
}
A better way (imo) would be to define different span counts in (many) different values directories and let the device automatically select which span count to use. For example:
values/integers.xml -> span_count=3
values-w480dp/integers.xml -> span_count=4
values-w600dp/integers.xml -> span_count=5
I'm posting this just in case someone gets weird column width as in my case.
I'm not able to comment on #s-marks's answer due to my low reputation. I applied his solution solution but I got some weird column width, so I modified checkedColumnWidth function as follows:
private int checkedColumnWidth(Context context, int columnWidth)
{
if (columnWidth <= 0)
{
/* Set default columnWidth value (48dp here). It is better to move this constant
to static constant on top, but we need context to convert it to dp, so can't really
do so. */
columnWidth = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 48,
context.getResources().getDisplayMetrics());
}
else
{
columnWidth = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, columnWidth,
context.getResources().getDisplayMetrics());
}
return columnWidth;
}
By converting the given column width into DP fixed the issue.
I conclusion above answers here
To accommodate orientation change on s-marks's answer, I added a check on width change (width from getWidth(), not column width).
private boolean mWidthChanged = true;
private int mWidth;
#Override
public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state)
{
int width = getWidth();
int height = getHeight();
if (width != mWidth) {
mWidthChanged = true;
mWidth = width;
}
if (mColumnWidthChanged && mColumnWidth > 0 && width > 0 && height > 0
|| mWidthChanged)
{
int totalSpace;
if (getOrientation() == VERTICAL)
{
totalSpace = width - getPaddingRight() - getPaddingLeft();
}
else
{
totalSpace = height - getPaddingTop() - getPaddingBottom();
}
int spanCount = Math.max(1, totalSpace / mColumnWidth);
setSpanCount(spanCount);
mColumnWidthChanged = false;
mWidthChanged = false;
}
super.onLayoutChildren(recycler, state);
}
The upvoted solution is fine, but handles the incoming values as pixels, which can trip you up if you're hardcoding values for testing and assuming dp. Easiest way is probably to put the column width in a dimension and read it when configuring the GridAutofitLayoutManager, which will automatically convert dp to correct pixel value:
new GridAutofitLayoutManager(getActivity(), (int)getActivity().getResources().getDimension(R.dimen.card_width))
Set minimal fixed width of imageView (144dp x 144dp for example)
When you create GridLayoutManager, you need to know how much columns will be with minimal size of imageView:
WindowManager wm = (WindowManager) this.getSystemService(Context.WINDOW_SERVICE); //Получаем размер экрана
Display display = wm.getDefaultDisplay();
Point point = new Point();
display.getSize(point);
int screenWidth = point.x; //Ширина экрана
int photoWidth = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 144, this.getResources().getDisplayMetrics()); //Переводим в точки
int columnsCount = screenWidth/photoWidth; //Число столбцов
GridLayoutManager gridLayoutManager = new GridLayoutManager(this, columnsCount);
recyclerView.setLayoutManager(gridLayoutManager);
After that you need to resize imageView in adapter if you have space in column. You may send newImageViewSize then inisilize adapter from activity there you calculate screen and column count:
#Override //Заполнение нашей плитки
public void onBindViewHolder(PhotoHolder holder, int position) {
...
ViewGroup.LayoutParams photoParams = holder.photo.getLayoutParams(); //Параметры нашей фотографии
int newImageViewSize = screenWidth/columnsCount; //Новый размер фотографии
photoParams.width = newImageViewSize; //Установка нового размера
photoParams.height = newImageViewSize;
holder.photo.setLayoutParams(photoParams); //Установка параметров
...
}
It works in both orientations. In vertical I have 2 columns and in horizontal - 4 columns. The result: https://i.stack.imgur.com/WHvyD.jpg
This is s.maks' class with a minor fix for when the recyclerview itself changes size. Such as when you deal with the orientation changes yourself (in the manifest android:configChanges="orientation|screenSize|keyboardHidden"), or some other reason the recyclerview might change size without the mColumnWidth changing. I also changed the int value it takes to be the resource of the size and allowed a constructor of no resource then setColumnWidth to do that yourself.
public class GridAutofitLayoutManager extends GridLayoutManager {
private Context context;
private float mColumnWidth;
private float currentColumnWidth = -1;
private int currentWidth = -1;
private int currentHeight = -1;
public GridAutofitLayoutManager(Context context) {
/* Initially set spanCount to 1, will be changed automatically later. */
super(context, 1);
this.context = context;
setColumnWidthByResource(-1);
}
public GridAutofitLayoutManager(Context context, int resource) {
this(context);
this.context = context;
setColumnWidthByResource(resource);
}
public GridAutofitLayoutManager(Context context, int resource, int orientation, boolean reverseLayout) {
/* Initially set spanCount to 1, will be changed automatically later. */
super(context, 1, orientation, reverseLayout);
this.context = context;
setColumnWidthByResource(resource);
}
public void setColumnWidthByResource(int resource) {
if (resource >= 0) {
mColumnWidth = context.getResources().getDimension(resource);
} else {
/* Set default columnWidth value (48dp here). It is better to move this constant
to static constant on top, but we need context to convert it to dp, so can't really
do so. */
mColumnWidth = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 48,
context.getResources().getDisplayMetrics());
}
}
public void setColumnWidth(float newColumnWidth) {
mColumnWidth = newColumnWidth;
}
#Override
public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) {
recalculateSpanCount();
super.onLayoutChildren(recycler, state);
}
public void recalculateSpanCount() {
int width = getWidth();
if (width <= 0) return;
int height = getHeight();
if (height <= 0) return;
if (mColumnWidth <= 0) return;
if ((width != currentWidth) || (height != currentHeight) || (mColumnWidth != currentColumnWidth)) {
int totalSpace;
if (getOrientation() == VERTICAL) {
totalSpace = width - getPaddingRight() - getPaddingLeft();
} else {
totalSpace = height - getPaddingTop() - getPaddingBottom();
}
int spanCount = (int) Math.max(1, Math.floor(totalSpace / mColumnWidth));
setSpanCount(spanCount);
currentColumnWidth = mColumnWidth;
currentWidth = width;
currentHeight = height;
}
}
}
I like s.maks' answer but I found another edge case: If you set the height of the RecyclerView to WRAP_CONTENT it may happen that the height of the recyclerview is calculated incorrectly based on an outdated spanCount value. The solution I found is a small modification of the proposed onLayoutChildren() method:
public void onLayoutChildren(#NonNull final RecyclerView.Recycler recycler, #NonNull final RecyclerView.State state) {
final int width = getWidth();
final int height = getHeight();
if (columnWidth > 0 && (width > 0 || getOrientation() == HORIZONTAL) && (height > 0 || getOrientation() == VERTICAL) && (isColumnWidthChanged || lastWidth != width || lastHeight != height)) {
final int totalSpace;
if (getOrientation() == VERTICAL) {
totalSpace = width - getPaddingRight() - getPaddingLeft();
} else {
totalSpace = height - getPaddingTop() - getPaddingBottom();
}
final int spanCount = Math.max(1, totalSpace / columnWidth);
if (getSpanCount() != spanCount) {
setSpanCount(spanCount);
}
isColumnWidthChanged = false;
}
lastWidth = width;
lastHeight = height;
super.onLayoutChildren(recycler, state);
}
Set spanCount to a large number (which is the max number of column) and set a custom SpanSizeLookup to the GridLayoutManager.
mLayoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
#Override
public int getSpanSize(int i) {
return SPAN_COUNT / (int) (mRecyclerView.getMeasuredWidth()/ CELL_SIZE_IN_PX);
}
});
It's a bit ugly, but it work.
I think a manager like AutoSpanGridLayoutManager would be the best solution, but i didn't find anything like that.
EDIT : There is a bug, on some device it add blank space to the right
Here's the relevant parts of a wrapper I've been using to auto-detect the span count. You initialize it by calling setGridLayoutManager with a R.layout.my_grid_item reference, and it figures out how many of those can fit on each row.
public class AutoSpanRecyclerView extends RecyclerView {
private int m_gridMinSpans;
private int m_gridItemLayoutId;
private LayoutRequester m_layoutRequester = new LayoutRequester();
public void setGridLayoutManager( int orientation, int itemLayoutId, int minSpans ) {
GridLayoutManager layoutManager = new GridLayoutManager( getContext(), 2, orientation, false );
m_gridItemLayoutId = itemLayoutId;
m_gridMinSpans = minSpans;
setLayoutManager( layoutManager );
}
#Override
protected void onLayout( boolean changed, int left, int top, int right, int bottom ) {
super.onLayout( changed, left, top, right, bottom );
if( changed ) {
LayoutManager layoutManager = getLayoutManager();
if( layoutManager instanceof GridLayoutManager ) {
final GridLayoutManager gridLayoutManager = (GridLayoutManager) layoutManager;
LayoutInflater inflater = LayoutInflater.from( getContext() );
View item = inflater.inflate( m_gridItemLayoutId, this, false );
int measureSpec = View.MeasureSpec.makeMeasureSpec( 0, View.MeasureSpec.UNSPECIFIED );
item.measure( measureSpec, measureSpec );
int itemWidth = item.getMeasuredWidth();
int recyclerViewWidth = getMeasuredWidth();
int spanCount = Math.max( m_gridMinSpans, recyclerViewWidth / itemWidth );
gridLayoutManager.setSpanCount( spanCount );
// if you call requestLayout() right here, you'll get ArrayIndexOutOfBoundsException when scrolling
post( m_layoutRequester );
}
}
}
private class LayoutRequester implements Runnable {
#Override
public void run() {
requestLayout();
}
}
}
Update : I solved this issue by using the method described in this answer
I'm a bit stuck with this issue, which I think should be pretty simple.
So my app downloads an image, and renders the bitmap in an ImageView, a child element of a RelativeLayout.
I would like the ImageView to fit the parent width, and to adapt it's size to keep the aspect ratio.
Here is my 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"
>
<RelativeLayout android:id="#+id/banner" android:layout_width="fill_parent" android:layout_height="wrap_content"></RelativeLayout>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="#string/hello"
/>
</LinearLayout>
And the code :
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
RelativeLayout banner = (RelativeLayout) findViewById(R.id.banner);
ImageView imgV = new ImageView(this);
imgV.setScaleType(ImageView.ScaleType.CENTER_CROP);
// I tried all the scale types : CENTER_INSIDE : same effect, FIT_CENTER : same effect...
imgV.setBackgroundColor(0x00FFFF00);
imgV.setAdjustViewBounds(Color.BLUE);
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.FILL_PARENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
banner.addView(imgV,params);
// Some code downloading the image stream
bitmap = BitmapFactory.decodeStream(stream);
imgV.setImageBitmap(bitmap);
}
Desired :
Result :
Thanks to #Julien and #js.
Here is complete solution of ImageView that will stretch bitmap height preserving aspect ratio even if bitmap is smaller than ImageView.
public class ResizableImageView extends ImageView {
public ResizableImageView(Context context, AttributeSet attrs) {
super(context, attrs);
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec){
Drawable d = getDrawable();
if(d!=null){
// ceil not round - avoid thin vertical gaps along the left/right edges
int width = MeasureSpec.getSize(widthMeasureSpec);
int height = (int) Math.ceil((float) width * (float) d.getIntrinsicHeight() / (float) d.getIntrinsicWidth());
setMeasuredDimension(width, height);
}else{
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}
}
You can use this class in your xml layouts instead ImageView.
<com.example.ResizableImageView
android:id="#+id/banner"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:src="#drawable/banner" />
You're probably looking for android:adjustViewBounds="true" in xml or imageView.setAdjustViewBounds(true) in Java.
As I mentioned in a comment, I subclassed the ImageView. I found my code, here you go :
protected class ResizableImageView extends ImageView
{
private Bitmap mBitmap;
// Constructor
public ResizableImageView(Context context)
{
super(context);
}
// Overriden methods
#Override
protected void onMeasure(int widthMeasureSpec,
int heightMeasureSpec) {
if(mBitmap != null)
{
int width = MeasureSpec.getSize(widthMeasureSpec);
int height = width * mBitmap.getHeight() / mBitmap.getWidth();
setMeasuredDimension(width, height);
}
else
{
super.onMeasure(widthMeasureSpec,
heightMeasureSpec);
}
}
#Override
public void setImageBitmap(Bitmap bitmap)
{
mBitmap = bitmap;
super.setImageBitmap(bitmap);
}
}
I think you should change your imgV width to "match_parent"
You should change the scale type to imgV.setScaleType(ImageView.ScaleType.CENTER_INSIDE);
I made a slight change to #Seraphim S's solution to account for cases where the image may be wide, and the view's bounds also wide (for example, rotating the device to landscape mode).
public class ResizableImageView extends ImageView {
public ResizableImageView(Context context, AttributeSet attrs) {
super(context, attrs);
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
Drawable d = getDrawable();
if (d != null) {
int width = MeasureSpec.getSize(widthMeasureSpec);
int height = MeasureSpec.getSize(heightMeasureSpec);
if (width >= height) {
width = (int) Math.ceil((float) height * (float) d.getIntrinsicWidth() / (float) d.getIntrinsicHeight());
} else {
height = (int) Math.ceil((float) width * (float) d.getIntrinsicHeight() / (float) d.getIntrinsicWidth());
}
setMeasuredDimension(width, height);
} else {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}
}