Bitmap of x cm's width and y cm's height - android

I am taking a picture using camera in my app and will email the picture to a certain email address. now i want the emailed picture's physical dimensions to be 10cm's in width and 8cm's in height. and the code i have tried is as follows:
1) declare a imageview in xml like below :
<ImageView
android:id="#+id/imageView3"
android:layout_width="100mm"
android:layout_height="80mm"
android:src="#drawable/ic_launcher" />
2) and later in java file :
final BitmapFactory.Options opts = new BitmapFactory.Options ();
opts.inSampleSize = 2;
final ImageView thumbNail = (ImageView)findViewById(R.id.imageView3);
thumbNail.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
// TODO Auto-generated method stub
thumbNail.setImageBitmap(Bitmap.createScaledBitmap (BitmapFactory.decodeFile(myPhoto.getPath(), opts), thumbNail.getWidth(), thumbNail.getHeight(), false));
}
});
As per the documentation the resulting bitmap should have width of 10cm's and height of 8cm's. but in xml file there is warning at these lines
android:layout_width="100mm"
android:layout_height="80mm"
Avoid using "mm" as units (it does not work accurately on all devices); use "dp" instead.
so i don't have a clue as to what i should do. so please give me a solution that will work on all devices.

This?
public static int mm2pixels(int val, Context current) {
DisplayMetrics metrics = current.getResources().getDisplayMetrics();
return (int)TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_MM, val, metrics);
}

i have used WarrenFaiths directions and came up with the below solution.
DisplayMetrics metrics = activity.getResources().getDisplayMetrics();
totalDIP_X = metrics.xdpi;
totalDIP_Y = metrics.ydpi;
totalDIP_X and totalDIP_Y represent the total number of DIPs per inch on the phone.
so if you want the bitmap to be 5cms*5cms on phone, which is equivalent to 1.968inch*1.968inch, we should use the below code.
imageView1.setImageBitmap(Bitmap.createScaledBitmap (aBitmap, (int)(1.968*totalDIP_X), (int)(1.968*totalDIP_Y), false));

Related

Detect device screen size

Hi i want to fit my app to all screen sizes and to do so i need to get the screen width and height.
but if i use this code for example
DisplayMetrics displaymetrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(displaymetrics);
int height = displaymetrics.heightPixels;
int width = displaymetrics.widthPixels
It gives me the pixels so there can happen a situation that it gives me the same dimentions for tablet and a smaller phone.
how can i get the actual screen size?
and another thing, i have a game i made with bitmaps and on my phone it is working fine but on tablet the bitmaps are too small how can i resize them according to screen size?
You need screen density and pixel size. (Number of pixels) / (dots per inch) gives screen size in inches.
See: getting the screen density programmatically in android?
DisplayMetrics displaymetrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(displaymetrics);
int height = displaymetrics.heightPixels;
int width = displaymetrics.widthPixels
int realWidth = (int)((float)width/metrics.density);
int realHeight = (int((float)height/metrics.density);
Answer to the second question depends on how are you loading your bitmaps. You should provide multiple sizes for different devices. Then you can use built-in scaling mechanism - simply place bitmaps in their matching drawable-(dpi)-(screen size) folders. Other way you would have to load images from assets folder and scale them if necessary.
For your 2nd problem of bitmap appearing too small on tablet, try to nine patch your image and then place those images in their respective folders (hdpi, mdpi, xhdpi, xxhdpi)
Make sure you use the high quality resolution image for nine patching otherwise your image will get stretch (poor quality).
You can nine patch your image from here also nine patching image
try this:
Display display = activity.getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
int width = size.x;
int height = size.y;
You can get screen dimensions with this code:
public int getScreenHeight() {
return getDisplay().getHeight();
}
private Display getDisplay() {
return ((WindowManager) getContext().getSystemService(
Context.WINDOW_SERVICE)).getDefaultDisplay();
}
public int getScreenWidth() {
return getDisplay().getWidth();
}
Try this.
Add this to onCreate() Method. Declare point!
WindowManager wm = ((WindowManager) getSystemService(WINDOW_SERVICE));
Display display = wm.getDefaultDisplay();
point = getDisplaySize(display);
//here is the method to get device size.
#Deprecated
#SuppressLint("NewApi")
private static Point getDisplaySize(final Display display) {
final Point point = new Point();
try {
display.getSize(point);
} catch (java.lang.NoSuchMethodError ignore) { // Older device
point.x = display.getWidth();
point.y = display.getHeight();
}
return point;
}

RelativeLayout for Android?

So I have been experimenting today with making an Android Application, but I have tried the LineairLayout to make a welcom screen for my application, but I cannot get it right..
So I tried RelativeLayout and I saw I can move my ImageViews and buttons to everywhere. So my question is if I will move the items to places like center, bottom left and bottom right. Would this be a problem or all phones since not all phones have the same dimensions?
public class WelcomeActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.welcome_screen_relative);
final ImageView logo = (ImageView) findViewById(R.id.myImageView);
DisplayMetrics metrics = Resources.getSystem().getDisplayMetrics();
int displayHeight = metrics.heightPixels;
int displayWidth = metrics.widthPixels;
float scaledDensity = metrics.scaledDensity;
BitmapFactory.Options dimensions = new BitmapFactory.Options();
dimensions.inJustDecodeBounds = true;
Bitmap mBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.log, dimensions);
int imageHeight = dimensions.outHeight;
int imageWidth = dimensions.outWidth;
float percentageToMoveViewDown = (float) 20.0;
float viewY_float = (float) ((displayHeight / 100.0) * percentageToMoveViewDown);
int viewY_int = Math.round(viewY_float);
RelativeLayout.LayoutParams view_Layout_params = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
view_Layout_params.topMargin = viewY_int;
logo.setLayoutParams(view_Layout_params);
logo.getLayoutParams().height = imageHeight;
logo.getLayoutParams().width = imageWidth;
}
Thats depends. If you give objects a fixed size of course it will. for dp/dpi make sure to test it in Emu or real devices. You can also create density and orientation specific layout to support many screens. Consider that there are not only changes in size but also aspect ration and resolution and DPI.
For most apps RelativeLayout is might be the right approach.
You can read an excelent article about it here: http://developer.android.com/guide/practices/screens_support.html
If the items have fixed sizes you always will have trouble with some phones. For the big ones it may be too small, for the small ones too big...
In my experience Androids small/normal/large screens won't help you much for configuring, since the differences are just too big.
If you want to make sure everything sits where it belongs to, you could get the device metrics. That way you don't even need to rely on center, but you can work with percentages to place everything where you want it to be. Plus you can set the sizes in percentage, which is great. Like you could say I want a button thats width is 50% of the screen, no matter how large the screen is. Its more work (maybe even overkill), but I really like that approach. Once you figured it out its basically just a bit copy paste at the start of your classes.
Example:
DisplayMetrics metrics = Resources.getSystem().getDisplayMetrics();
int displayHeight = metrics.heightPixels;
int displayWidth = metrics.widthPixels;
float scaledDensity = metrics.scaledDensity;
//move some View 20% down:
float percentageToMoveViewDown = (float) 20.0;
float viewY_float = (float) ((displayHeight / 100.0) * percentageToMoveViewDown);
int viewY_int = Math.round(viewY_float);
RelativeLayout.LayoutParams view_Layout_params = new RelativeLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
view_Layout_params.topMargin = viewY_int;
view.setLayoutParams(view_Layout_params);
//even works with text size for a TextView:
float percentageToResizeTextViewTextSize = (float) 3.1;
float textViewTextSize_float = (float) ((displayHeight / 100.0) * percentageToResizeTextViewTextSize);
int textViewTextSize_int = Math.round(textViewTextSize_float / scaledDensity);
textView.setTextSize(textViewTextSize_int);
Just a side note for the overkill thing: This should be only necessary if you want to support small devices (they mostly run something like android 2.3, but still are sold as budget phones) and big devices as well, but the trouble with the big ones is not as big as the trouble with the small ones. I personally rather put more effort in it than less, you never know.
Edit: ImageView by code
The easiest way is to do it hybridly, using xml and code. Note that you will have to change width and height if you set it to 0 in xml like in the following example.
Just place it in the xml where you would anyways, somewhere in your RelativeLayout.
In your xml:
<ImageView
android:id="#+id/myImageView"
android:layout_width="0dp"
android:layout_height="0dp" />
In your Code:
ImageView myImageView = (ImageView)findViewById(R.id.myImageView);
You now can work with that myImageView as I did it with view and textView. You can even set the image right here in code.
This imageView with the size of 0,0 is now placed where it would have been before. Now you could set the width to like 50% of the screenwidth and the height to...lets say 40% of the screen height. Then You would need to place it. If you want to center it you know that there must be 25% of the screen on each side, so you can add 25% as left and right margin.
Edit 2: maintain original imagesize
If you want to keep the original size of a image in your drawables, you can get its width and height like this:
BitmapFactory.Options dimensions = new BitmapFactory.Options();
dimensions.inJustDecodeBounds = true;
Bitmap mBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.yourImageName, dimensions);
int imageHeight = dimensions.outHeight;
int imageWidth = dimensions.outWidth;
Now that you have that, you could use it to calculate the aspect ratio to keep it.
Now since you know the devices width and height, you can easily calculate how much of the screen this image will need.(imageheight/screenheight*100 = your percentage of the screen you want the imageviews height to be). So the Height you set to the imageview would be displayHeight / 100 * (imageHeight / displayHeight * 100).
How to place that?
Now if you take a Screenheight of 100 and a imageheight of 80 you get 80%. You would now take this percentage and divide it from 100. Divide that /2 and you know how much space you would have as top and bottom margins if you wanted it to be placed in the middle of the screen (you would have to do the same for width).
Caution: If you don't want it to be relative to the screensize but the original size, that percentage approach is kind of pointless. If you do to your image what I just described, it may still be too big for small devices and too small for big ones. Instead you could think about what percentage would look good in proportion to the rest of the stuff on the screen and resize it to that, since it would have that relative size on all devices.
Edit 3:
Since you load the image in original size, it will be small on big devices if it is a small image.
//first you need to know your aspect ratio.
float ratio = imageWidth / imageHeight;
//lets say you wanted the image to be 50% of the screen:
float percentageToResizeImageTo = (float) 50.0;
float imageX_float = (float) ((displayHeight / 100.0) * percentageToResizeImageTo);
int imageX_int = Math.round(imageX_float);
//now you know how much 50% of the screen is
imageWidth = imageX_int;
imageHeight = imageWidth * ratio;
RelativeLayout.LayoutParams view_Layout_params = new RelativeLayout.LayoutParams(imageHeight, imageWidth);
view_Layout_params.topMargin = viewY_int;
logo.setLayoutParams(view_Layout_params);
logo.setScaleType(ImageView.ScaleType.Fit_XY);

Android - Out of Memory Exception in ScrollView

I know this must be one of the most asked things at SO, but none of the other answers gave me a solution. But from reading the other answers, looks like I'll need to redesign the way the App is working.
It's like this, we have a ScrollView, which will inflate some views. A ListView can't be used in this situation, because to behave the way we want it would require extending the ListView, and this is something we don't want to do (even though this seems to be our only solution to our current way of showing items, because of this OOM exception). The list can have a lot of columns per row, and the bigger the screen, more columns it will have.
Each inflated View has a layout displaying some info from the database, including a picture. This picture is stored through a byte array. It's any picture taken with the device camera. Currently every photo (byte array) is taking 800kb to 1mb, which seems a lot to me. Now the list have 30+ items. I took photos until the OOM happened, and it happened when I took a total of 6 photos (occasionally 7). That would be 8mb-9mb of data. Everytime I go to other Activity, and go back to the Activity the ScrollView is in, the list needs to be repopulated.
This is the snippet of the PopulateList method:
if (item.getImg() != null) {
if (App.debug) {
Log.d(TAG, "Setting bmp.");
}
Bitmap bmp = App.byteArrayToBmp(item.getImg());
imgV.setImageBitmap(bmp);
}
Every inflated View will open an 'Advanced Dialog', which will contain other info. Maybe the Image could be there instead on the list (meaning that there would be only 1 bitmap, as every inflated View shares the same advanced dialog). Or I could extend the ListView and benefit from it recycling method (It's not a good solution as I though it would be considering more than 6 items can be at the screen). Another thing that bothers me is every picture having 800kb. Seems like a lot for a 128x128.
This is the setup for the size:
cameraParams.setPictureSize(App.pxToDpi(128), App.pxToDpi(128));
cameraParams.setPictureFormat(PixelFormat.JPEG);
camera.setParameters(cameraParams);
public static int pxToDpi(int px) {
final int scale = app.getApplicationContext().getResources().getDisplayMetrics().densityDpi;
int pixels = (int) px * (scale / 160);
return pixels;
}
So, do you think there is a solution to my issue keeping the current model of my App, or will I need to reformulate?
EDIT: The bitmap method:
public static Bitmap byteArrayToBmp(byte[] byteArray) {
Bitmap img = null;
BitmapFactory.Options opts = new BitmapFactory.Options();
opts.inSampleSize = 2;
img = BitmapFactory.decodeByteArray(byteArray, 0, byteArray.length, opts);
return img;
}
You might want to look at the Official Android Training docs, they've just been updated:
Check out Displaying Bitmaps Efficiently with the lesson: Loading Large Bitmaps Efficiently that goes over this.
Basically you can decode the image using sampleSize to decode it to the width and height you want:
public static int calculateInSampleSize(
BitmapFactory.Options options, int reqWidth, int reqHeight) {
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;
if (height > reqHeight || width > reqWidth) {
if (width > height) {
inSampleSize = Math.round((float)height / (float)reqHeight);
} else {
inSampleSize = Math.round((float)width / (float)reqWidth);
}
}
return inSampleSize;
}
Explained in much great detail in the links above

"Bitmap too large to be uploaded into a texture"

I'm loading a bitmap into an ImageView, and seeing this error. I gather this limit relates to a size limit for OpenGL hardware textures (2048x2048). The image I need to load is a pinch-zoom image of about 4,000 pixels high.
I've tried turning off hardware acceleration in the manifest, but no joy.
<application
android:hardwareAccelerated="false"
....
>
Is it possible to load an image larger than 2048 pixels into an ImageView?
This isn't a direct answer to the question (loading images >2048), but a possible solution for anyone experiencing the error.
In my case, the image was smaller than 2048 in both dimensions (1280x727 to be exact) and the issue was specifically experienced on a Galaxy Nexus. The image was in the drawable folder and none of the qualified folders. Android assumes drawables without a density qualifier are mdpi and scales them up or down for other densities, in this case scaled up 2x for xhdpi. Moving the culprit image to drawable-nodpi to prevent scaling solved the problem.
I have scaled down the image in this way:
ImageView iv = (ImageView)waypointListView.findViewById(R.id.waypoint_picker_photo);
Bitmap d = new BitmapDrawable(ctx.getResources() , w.photo.getAbsolutePath()).getBitmap();
int nh = (int) ( d.getHeight() * (512.0 / d.getWidth()) );
Bitmap scaled = Bitmap.createScaledBitmap(d, 512, nh, true);
iv.setImageBitmap(scaled);
All rendering is based on OpenGL, so no you can't go over this limit (GL_MAX_TEXTURE_SIZE depends on the device, but the minimum is 2048x2048, so any image lower than 2048x2048 will fit).
With such big images, if you want to zoom in out, and in a mobile, you should setup a system similar to what you see in google maps for example. With the image split in several pieces, and several definitions.
Or you could scale down the image before displaying it (see user1352407's answer on this question).
And also, be careful to which folder you put the image into, Android can automatically scale up images. Have a look at Pilot_51's answer below on this question.
Instead of spending hours upon hours trying to write/debug all this downsampling code manually, why not use Picasso? It was made for dealing with bitmaps of all types and/or sizes.
I have used this single line of code to remove my "bitmap too large...." problem:
Picasso.load(resourceId).fit().centerCrop().into(imageView);
Addition of the following 2 attributes in (AndroidManifest.xml) worked for me:
android:largeHeap="true"
android:hardwareAccelerated="false"
Changing the image file to drawable-nodpi folder from drawable folder worked for me.
I used Picasso and had the same problem. image was too large at least in on size, width or height. finally I found the solution here. you can scale the large image down according to display size and also keep the aspect ratio:
public Point getDisplaySize(Display display) {
Point size = new Point();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB_MR2) {
display.getSize(size);
} else {
int width = display.getWidth();
int height = display.getHeight();
size = new Point(width, height);
}
return size;
}
and use this method for loading image by Picasso:
final Point displySize = getDisplaySize(getWindowManager().getDefaultDisplay());
final int size = (int) Math.ceil(Math.sqrt(displySize.x * displySize.y));
Picasso.with(this)
.load(urlSource)
.resize(size, size)
.centerInside()
.into(imageViewd);
also for better performance you can download the image according to width and height of the display screen, not whole the image:
public String reviseImageUrl(final Integer displayWidth, final Integer displayHeight,
final String originalImageUrl) {
final String revisedImageUrl;
if (displayWidth == null && displayHeight == null) {
revisedImageUrl = originalImageUrl;
} else {
final Uri.Builder uriBuilder = Uri.parse(originalImageUrl).buildUpon();
if (displayWidth != null && displayWidth > 0) {
uriBuilder.appendQueryParameter(QUERY_KEY_DISPLAY_WIDTH, String.valueOf(displayWidth));
}
if (displayHeight != null && displayHeight > 0) {
uriBuilder.appendQueryParameter(QUERY_KEY_DISPLAY_HEIGHT, String.valueOf(displayHeight));
}
revisedImageUrl = uriBuilder.toString();
}
return revisedImageUrl;
}
final String newImageUlr = reviseImageUrl(displySize.x, displySize.y, urlSource);
and then:
Picasso.with(this)
.load(newImageUlr)
.resize(size, size)
.centerInside()
.into(imageViewd);
EDIT: getDisplaySize()
display.getWidth()/getHeight() is deprecated. Instead of Display use DisplayMetrics.
public Point getDisplaySize(DisplayMetrics displayMetrics) {
int width = displayMetrics.widthPixels;
int height = displayMetrics.heightPixels;
return new Point(width, height);
}
BitmapRegionDecoder does the trick.
You can override onDraw(Canvas canvas), start a new Thread and decode the area visible to the user.
As pointed by Larcho, starting from API level 10, you can use BitmapRegionDecoder to load specific regions from an image and with that, you can accomplish to show a large image in high resolution by allocating in memory just the needed regions. I've recently developed a lib that provides the visualisation of large images with touch gesture handling. The source code and samples are available here.
View level
You can disable hardware acceleration for an individual view at runtime with the following code:
myView.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
I ran through same problem, here is my solution. set the width of image same as android screen width and then scales the height
Bitmap myBitmap = BitmapFactory.decodeFile(image.getAbsolutePath());
Display display = getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
int width = size.x;
int height = size.y;
Log.e("Screen width ", " "+width);
Log.e("Screen height ", " "+height);
Log.e("img width ", " "+myBitmap.getWidth());
Log.e("img height ", " "+myBitmap.getHeight());
float scaleHt =(float) width/myBitmap.getWidth();
Log.e("Scaled percent ", " "+scaleHt);
Bitmap scaled = Bitmap.createScaledBitmap(myBitmap, width, (int)(myBitmap.getWidth()*scaleHt), true);
myImage.setImageBitmap(scaled);
This is better for any size android screen. let me know if it works for you.
Scale down image:
BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
// Set height and width in options, does not return an image and no resource taken
BitmapFactory.decodeStream(imagefile, null, options);
int pow = 0;
while (options.outHeight >> pow > reqHeight || options.outWidth >> pow > reqWidth)
pow += 1;
options.inSampleSize = 1 << pow;
options.inJustDecodeBounds = false;
image = BitmapFactory.decodeStream(imagefile, null, options);
The image will be scaled down at the size of reqHeight and reqWidth. As I understand inSampleSize only take in a power of 2 values.
Use Glide library instead of directly loading into imageview
Glide : https://github.com/bumptech/glide
Glide.with(this).load(Uri.parse(filelocation))).into(img_selectPassportPic);
I tried all the solutions above, one-after-the-other, for quite many hours, and none seemed to work! Finally, I decided to look around for an official example concerning capturing images with Android's camera, and displaying them. The official example (here), finally gave me the only method that worked. Below I present the solution I found in that example app:
public void setThumbnailImageAndSave(final ImageView imgView, File imgFile) {
/* There isn't enough memory to open up more than a couple camera photos */
/* So pre-scale the target bitmap into which the file is decoded */
/* Get the size of the ImageView */
int targetW = imgView.getWidth();
int targetH = imgView.getHeight();
/* Get the size of the image */
BitmapFactory.Options bmOptions = new BitmapFactory.Options();
bmOptions.inJustDecodeBounds = true;
BitmapFactory.decodeFile(imgFile.getAbsolutePath(), bmOptions);
int photoW = bmOptions.outWidth;
int photoH = bmOptions.outHeight;
/* Figure out which way needs to be reduced less */
int scaleFactor = 1;
if ((targetW > 0) || (targetH > 0)) {
scaleFactor = Math.min(photoW/targetW, photoH/targetH);
}
/* Set bitmap options to scale the image decode target */
bmOptions.inJustDecodeBounds = false;
bmOptions.inSampleSize = scaleFactor;
bmOptions.inPurgeable = true;
/* Decode the JPEG file into a Bitmap */
Bitmap bitmap = BitmapFactory.decodeFile(imgFile.getAbsolutePath(), bmOptions);
/* Associate the Bitmap to the ImageView */
imgView.setImageBitmap(bitmap);
imgView.setVisibility(View.VISIBLE);
}
NOTE FOR THOSE WHO WANT TO PUT IMAGES OF SMALL SIZE:
Pilot_51's solution (moving your images to drawable-nodpi folder) works, but has another problem:
It makes images TOO SMALL on screen unless the images are resized to a very large (like 2000 x 3800) resolution to fit screen -- then it makes your app heavier.
SOLUTION: put your image files in drawable-hdpi -- It worked like a charm for me.
Using the correct drawable subfolder solved it for me. My solution was to put my full resolution image (1920x1200) into the drawable-xhdpi folder, instead of the drawable folder.
I also put a scaled down image (1280x800) into the drawable-hdpi folder.
These two resolutions match the 2013 and 2012 Nexus 7 tablets I'm programming. I also tested the solution on some other tablets.
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
///*
if (requestCode == PICK_FROM_FILE && resultCode == RESULT_OK && null != data){
uri = data.getData();
String[] prjection ={MediaStore.Images.Media.DATA};
Cursor cursor = getContentResolver().query(uri,prjection,null,null,null);
cursor.moveToFirst();
int columnIndex = cursor.getColumnIndex(prjection[0]);
ImagePath = cursor.getString(columnIndex);
cursor.close();
FixBitmap = BitmapFactory.decodeFile(ImagePath);
ShowSelectedImage = (ImageView)findViewById(R.id.imageView);
// FixBitmap = new BitmapDrawable(ImagePath);
int nh = (int) ( FixBitmap.getHeight() * (512.0 / FixBitmap.getWidth()) );
FixBitmap = Bitmap.createScaledBitmap(FixBitmap, 512, nh, true);
// ShowSelectedImage.setImageBitmap(BitmapFactory.decodeFile(ImagePath));
ShowSelectedImage.setImageBitmap(FixBitmap);
}
}
This code is work

How to get the Dimensions of a Drawable in an ImageView? [duplicate]

This question already has answers here:
How to get the width and height of an android.widget.ImageView?
(10 answers)
Closed 6 years ago.
What is the best way to retrieve the dimensions of the Drawable in an ImageView?
My ImageView has an Init-Method where I create the ImageView:
private void init() {
coverImg = new ImageView(context);
coverImg.setScaleType(ScaleType.FIT_START);
coverImg.setImageDrawable(getResources().getDrawable(R.drawable.store_blind_cover));
addView(coverImg);
}
At some point during the layout oder measure process I need the exact dimensions of the Drawable to adjust the rest of my Components around it.
coverImg.getHeight() and coverImg.getMeasuredHeight() don't return the results that I need and if I use coverImg.getDrawable().getBounds() I get the dimensions before it was scaled by the ImageView.
Thanks for your help!
Just tried this out and it works for me:
int finalHeight, finalWidth;
final ImageView iv = (ImageView)findViewById(R.id.scaled_image);
final TextView tv = (TextView)findViewById(R.id.size_label);
ViewTreeObserver vto = iv.getViewTreeObserver();
vto.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
public boolean onPreDraw() {
// Remove after the first run so it doesn't fire forever
iv.getViewTreeObserver().removeOnPreDrawListener(this);
finalHeight = iv.getMeasuredHeight();
finalWidth = iv.getMeasuredWidth();
tv.setText("Height: " + finalHeight + " Width: " + finalWidth);
return true;
}
});
The ViewTreeObserver will let you monitor the layout just prior to drawing it (i.e. everything has been measured already) and from here you can get the scaled measurements from the ImageView.
Call getIntrinsicHeight and getIntrinsicWidth on the drawable.
public int getIntrinsicHeight ()
Since: API Level 1
Return the intrinsic height of the underlying drawable object.
Returns -1 if it has no intrinsic height, such as with a solid color.
public int getIntrinsicWidth ()
Since: API Level 1
Return the intrinsic width of the underlying drawable object.
Returns -1 if it has no intrinsic width, such as with a solid color.
http://developer.android.com/reference/android/graphics/drawable/Drawable.html#getIntrinsicHeight()
This is the size of the original drawable. I think this is what you want.
The most reliable and powerful way to get drawable dimensions for me has been to use BitmapFactory to decode a Bitmap. It's very flexible - it can decode images from a drawable resource, file, or other different sources.
Here's how to get dimensions from a drawable resource with BitmapFactory:
BitmapFactory.Options o = new BitmapFactory.Options();
o.inTargetDensity = DisplayMetrics.DENSITY_DEFAULT;
Bitmap bmp = BitmapFactory.decodeResource(activity.getResources(),
R.drawable.sample_image, o);
int w = bmp.getWidth();
int h = bmp.getHeight();
Be careful if you use multiple density drawable folders under res, and make sure you specify inTargetDensity on your BitmapFactory.Options to get the drawable of the density you want.
Efficient way to get Width & Height of Drawable:
Drawable drawable = getResources().getDrawable(R.drawable.ic_home);
int width = drawable.getIntrinsicWidth();
int height = drawable.getIntrinsicHeight();
Log.i("Drawable dimension : W-H", width+"-"+height);
Hope this will help you.
this solved my problem. It decode the size of image boundary without really load the whole image.
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
Bitmap bmp = BitmapFactory.decodeResource(this.getResources(), R.drawable.img , o);
int w = o.outWidth;
int h = o.outHeight;

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