Develop Reference

Set ImageView max height using code

I want to set Max Height to Imageview that it can have when the image is loaded. Initial I've set android:height="wrap_content" in XML to make room for other views. But after the image is loaded sometimes it covers the whole screen of mobile and i can't see other views and i want to limit the height to some certain value. Please!! any help is appreciated.. cheers

A structure describing general information about a display, such as
its size, density, and font scaling.
DisplayMetrics metrics = getResources().getDisplayMetrics();
int DeviceTotalWidth = metrics.widthPixels;
int DeviceTotalHeight = metrics.heightPixels;
/*
*
* Adding Height Respect To Device
* */
ImageView ImageViewObj=(ImageView)findViewById(R.id.ImageViewId);
ImageViewObj.getLayoutParams().height= (int) (DeviceTotalHeight);

Get the screen height, and use it to set some ratio like Sunny said.
/* get the screen height in pixels */
public static int getScreenHeight(WindowManager windowManager) {
Display display = windowManager.getDefaultDisplay();
Point point = new Point();
display.getSize(point);
return point.y;
}
/* take an imageview, and set its height to desired float ratio */
public static void setImageHeight(Activity activity, ImageView imageView, float ratio) {
int h = getScreenHeight(activity.getWindowManager());
imageView.getLayoutParams().height = (int)(h*ratio);
}
Then in onCreate(....), try doing
ImageView imageView = (ImageView) findViewById(R.id.whatever);
setImageHeight(imageView, 0.4f); /* 40% */

Android: How to find scale ratio of background image

OK, so I have an image that I am using in an ImageView to fill the screen. I am keeping the aspect ratio by using scaletype="centerCrop", as seen here:
<ImageView
android:id="#+id/imageView1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:scaleType="centerCrop"
android:src="#drawable/full_bg" />
In code, how do I go about finding the scale ratio, or scale factor, that resulted from the original image to the scaled image? I need to know so I can apply this same ratio to a button positioned strategically on top of the background. This is what I have tried to get the scale ratio:
ImageView view = (ImageView) findViewById(R.id.imageView1);
Log.i("Test", "x scale = " + Float.toString(view.getScaleX()));
This returns a 1.0 (unscaled) which isn't what I'm looking for. I also tried getting the dimensions of the scaled Bitmap instead of the ImageView, which also gives me the original image size (540px):
ImageView view = (ImageView) findViewById(R.id.imageView1);
Drawable drawing = view.getDrawable();
Bitmap bitmap = ((BitmapDrawable)drawing).getBitmap();
Log.i("Test", "width = " + Integer.toString(bitmap.getWidth()));
Am I approaching this all wrong? I can't find anything to help me figure this out. Any help would be much appreciated!

Try this: I got this to change the image size depending on the size of the screen, but this could be easily changed by changing
int width = metrics.widthPixels;
to be
int width = bitmap.getWidth();
or whatever you want it to be scaled to. Note width is the size you're going to.
public static void changeImageSize(ImageView object, Context context){
DisplayMetrics metrics = new DisplayMetrics();
((WindowManager)context.getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay().getMetrics(metrics);
int width = metrics.widthPixels;
int height = metrics.heightPixels;
BitmapDrawable bmap = (BitmapDrawable) object.getDrawable();
RelativeLayout.LayoutParams layout = (LayoutParams) object.getLayoutParams();
float bmapWidth = bmap.getBitmap().getWidth();
float bmapHeight = bmap.getBitmap().getHeight();
int newBmapWidth = (int) (bmapWidth*width/480);
int newBmapHeight = (int) (bmapHeight*height/800);
layout.width = newBmapWidth;
layout.height = newBmapHeight;
object.setLayoutParams(layout);
}

Aligning a view to an ImageView in different resolutions

The problem with properly handling multiple screen sizes on Android has been talked all over thousands of times. However I couldn't find a solution to m problem. In a nutshell I need to align my custom progress bar over an imageView. I've got 3 set of drawables for the imageView - ldpi(240x400), mdpi(320x480), hdpi(480x800). I align my custom view in Java with the following code:
//get screen density
float density = getBaseContext().getResources().getDisplayMetrics().density;
//set the progress bar position according to screen density
if ( density == 1.0f)
{
ImageView micImage = ((ImageView) findViewById(R.id.imageViewClk));
Drawable drawing = micImage.getDrawable();
Bitmap bitmap = ((BitmapDrawable)drawing).getBitmap();
// Get current dimensions
int width = bitmap.getWidth();
int height = bitmap.getHeight();
LayoutParams params = new LayoutParams((int)(height/13.94), (int)(height/13.94));
params.setMargins((int)(width/2.30), 0, 0, (int)(height/2.75));
params.addRule(RelativeLayout.ALIGN_LEFT,R.id.imageViewClk);
params.addRule(RelativeLayout.ALIGN_BOTTOM,R.id.imageViewClk);
myCustomTwistedProgressBar.setLayoutParams(params);
}else if ( density == 1.5f ){
ImageView micImage = ((ImageView) findViewById(R.id.imageViewClk));
Drawable drawing = micImage.getDrawable();
Bitmap bitmap = ((BitmapDrawable)drawing).getBitmap();
int width = bitmap.getWidth();
int height = bitmap.getHeight();
LayoutParams params = new LayoutParams((int)Math.round(height/14.13), (int)Math.round(height/14.13));
params.setMargins((int)Math.round( width/2.27), 0, 0, (int)Math.round(height/2.91));
params.addRule(RelativeLayout.ALIGN_LEFT,R.id.imageViewClk);
params.addRule(RelativeLayout.ALIGN_BOTTOM,R.id.imageViewClk);
myCustomTwistedProgressBar.setLayoutParams(params);
}else if ( density == 0.75f ){
ImageView micImage = ((ImageView) findViewById(R.id.imageViewClk));
Drawable drawing = micImage.getDrawable();
Bitmap bitmap = ((BitmapDrawable)drawing).getBitmap();
// Get current dimensions
int width = bitmap.getWidth();
int height = bitmap.getHeight();
LayoutParams params = new LayoutParams((int)(height/14.88), (int)(height/14.88));
params.setMargins((int)(width/2.27), 0, 0, (int)(height/2.69));
params.addRule(RelativeLayout.ALIGN_LEFT,R.id.imageViewClk);
params.addRule(RelativeLayout.ALIGN_BOTTOM,R.id.imageViewClk);
myCustomTwistedProgressBar.setLayoutParams(params);
}
Everything worked fined on different screen sizes however when I tried to check on 480x854 resolution the vertical alignment of the custom view was incorrect. Checked with 480x800 on the same screen size and it again works. I than went for a big jump and checked in GalaxyTab and the horizontal and vertical alignments were wrong. Now my first though was that the bitmap width and height were the one of the image not the actual resized imageview. So I spent a lot of time on trying to get the real size of the imageview and even went for viewTreeObserver but the results were all the same - the correct, unchanged (unscaled?) bitmap size. So being positive that the problem is not here I couldn't get through further. Does anyone have an idea why the alignment is not working correctly?
PS: as for the image view in layout xml file I have 2 configurations for long and notlong but this image has the same description in both:
<ImageView
android:src="#drawable/cloking"
android:id="#+id/imageViewClk"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:layout_centerHorizontal="true"
android:layout_above="#+id/imageViewProcess"
android:adjustViewBounds="true"
android:cropToPadding="false"
android:layout_marginTop="60dp"
android:scaleType="fitXY">
</ImageView>

Android will scale the image but it will maintain aspect ratio for the image. You can't control aspect ratio with layout settings (as far as I know). I would solve that problem by choosing few screen ratios that I want to support and making few more resources (images that would have aspect ratios that you support). Code would look like this:
Display display = getWindowManager().getDefaultDisplay();
int width = display.getWidth();
int height = display.getHeight();
ImageView image = (ImageView) findViewById(R.id.imageViewClk);
if(width/height == aspectRatio1)
{
image.setImageResource(R.id.imageAspect1);
} else if( width/height == aspectRatio2...

Android Scale Image to largest size

Hi i'm working on an application that will be loading images and i'm looking to scale each image to it's largest possible size for instance if the image is a landscape image (if width is larger than height) i would like to stretch the width to fill the width of the phone and scale height to keep it's aspect ratio. If the height is larger than the width i.e. a portrait image the image should be scaled to fit the height of the phone and width should then adjust to keep the aspect ratio i've had a bit of trouble getting this to work here's what i've done so far though any help would be greatly appreciated.
final ImageView i = new ImageView(mContext);
i.setImageResource(mImageIds[position]);
i.setBackgroundResource(android.R.color.black);
//TODO need to get actual size of drawable not view size which is 0
ViewTreeObserver vto = i.getViewTreeObserver();
vto.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
public boolean onPreDraw() {
int w = i.getMeasuredWidth();
int h = i.getMeasuredHeight();
Display display = getWindowManager().getDefaultDisplay();
int width = display.getWidth();
int height = display.getHeight();
if(w <= h){
//TODO need to think about landscape
h = height - convertDpToPixel(50, context);
w = w*(width);
}else{
h = h*(height);
w = width;
}
//TODO set imageview to w and h
return true;
}
});

for get Display width , height
DisplayMetrics displaymetrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(displaymetrics);
int height = displaymetrics.heightPixels;
int wwidth = displaymetrics.widthPixels;
For Resize Imageview
ImageView img=(ImageView)findViewById(R.id.ImageView01);
Bitmap bmp=BitmapFactory.decodeResource(getResources(), R.drawable.sc01);
Bitmap resizedbitmap=Bitmap.createScaledBitmap(bmp, width, height, true);
img.setImageBitmap(resizedbitmap);

Increase either the height or the width to their maximum, depending on which is already greater.
Now, let's say you're working with a landscape image:
You've already expanded the width to it's maximum size, the display's width
The side you expanded is the width of the image, so assuming the display width = width and the image's width = w:
width / w = r
So r would be the ratio between the display width and the image width. Now you need to use this to increase your height.
Simply multiply the height by the ratio, and set the image's new height to the resulting number.
If you end up with a portait image... well, I think you'll be able to figure it out. It's pretty much the same thing.
After all that, I think it would just be a matter of positioning the image in the center of the screen.

Android Changing image size depending on Screen Size?

So I need to change the size of an image depending on the area of the screen. The image will have to be half of the screen height, because otherwise it overlaps some text.
So Height= 1/2 Screen Height.
Width = Height*Aspect Ratio (Just trying to keep the aspect ratio the same)
I found something that was:
Display myDisplay = ((WindowManager) getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
int width =myDisplay.getWidth();
int height=myDisplay.getHeight();
But how would I change image height in java? or even XML if possible? I can't seem to find a working answer.

You can do this with LayoutParams in code. Unfortunately there's no way to specify percentages through XML (not directly, you can mess around with weights, but that's not always going to help, and it won't keep your aspect ratio), but this should work for you:
//assuming your layout is in a LinearLayout as its root
LinearLayout layout = (LinearLayout)findViewById(R.id.rootlayout);
ImageView image = new ImageView(this);
image.setImageResource(R.drawable.image);
int newHeight = getWindowManager().getDefaultDisplay().getHeight() / 2;
int orgWidth = image.getDrawable().getIntrinsicWidth();
int orgHeight = image.getDrawable().getIntrinsicHeight();
//double check my math, this should be right, though
int newWidth = Math.floor((orgWidth * newHeight) / orgHeight);
//Use RelativeLayout.LayoutParams if your parent is a RelativeLayout
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
newWidth, newHeight);
image.setLayoutParams(params);
image.setScaleType(ImageView.ScaleType.CENTER_CROP);
layout.addView(image);
Might be overcomplicated, maybe there's an easier way? This is what I'd first try, though.