Develop Reference

Views in GridLayout are not equal

I'm creating a GridLayout named channelView, which has bitmap icons as its views. But when the app runs on a device android 4.4.2 (only then) the first icon is smaller than the others.
Here is my code:
File file = new File(CatchupActivity.this.getApplicationContext().getFilesDir(),
Util.getFileNameFromUrl(tch.icon));
Bitmap icon;
try{
BitmapFactory.Options options = new BitmapFactory.Options();
options.inPreferredConfig =Bitmap.Config.ARGB_8888;
options.outHeight = 150;
options.outWidth = 150;
icon = BitmapFactory.decodeFile(file.getAbsolutePath(), options);
}
catch(Exception e)
{
icon = Bitmap.createBitmap(120,120,Bitmap.Config.ARGB_8888);
}
channelIcon.setBackgroundResource(R.drawable.catchup_selector);
GridLayout.LayoutParams pp = new GridLayout.LayoutParams();
pp.setMargins(5, 5, 5, 5);
channelIcon.setImageBitmap(icon);
channelView.addView(channelIcon, pp);
And a screenshoot:
Why is this happening?

outWidth and outHeight are output parameters, used by inJustDecodeBounds. Setting them yourself has no meaning.
In this case, it would appear that the GridLayout cell is the right size, as the rows and columns are all set up properly. Since the default width and height for children of a GridLayout are wrap_content and wrap_content, this would suggest that the image that you are loading into the ImageView is smaller than the others.

Getting size from view that places inside a ViewGroup with GONE visibility (programatically it will be set as VISIBLE)

I'm trying to get a picture from my camera device, to save it, and show a preview in a ImageView.
My ImageView (named imagePreview) is defined inside the following layout:
<LinearLayout
android:id="#+id/ll_selected_image"
android:layout_width="match_parent"
android:layout_height="300dp"
android:orientation="vertical"
android:layout_gravity="center_horizontal"
android:visibility="gone"> <!-- at first this is GONE -->
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:id="#+id/imagePreview"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_centerInParent="true"/>
</RelativeLayout>
</LinearLayout>
When the image is acquired from the camera, I try to scale my image following this document, which code is:
private void setPic() {
// Get the dimensions of the View
int targetW = mImageView.getWidth();
int targetH = mImageView.getHeight();
// Get the dimensions of the bitmap
BitmapFactory.Options bmOptions = new BitmapFactory.Options();
bmOptions.inJustDecodeBounds = true;
BitmapFactory.decodeFile(mCurrentPhotoPath, bmOptions);
int photoW = bmOptions.outWidth;
int photoH = bmOptions.outHeight;
// Determine how much to scale down the image
int scaleFactor = Math.min(photoW/targetW, photoH/targetH);
// Decode the image file into a Bitmap sized to fill the View
bmOptions.inJustDecodeBounds = false;
bmOptions.inSampleSize = scaleFactor;
bmOptions.inPurgeable = true;
Bitmap bitmap = BitmapFactory.decodeFile(mCurrentPhotoPath, bmOptions);
mImageView.setImageBitmap(bitmap);
}
The problem is that I obtain a "division by zero" mImageView.getWidth(); and mImageView.getHeight(); return zero.
Note that the visibility of the parent LinearLayout is setted to GONE. Then, my application sets programmatically it to VISIBLE.
If I remove GONE, and I add VISIBLE instead, all works good!
The strange thing is that I have tried to add in the setPic(), as first code lines, the following code:
if(ivSelectedImage.getVisibility() == View.VISIBLE)
Log.i(TAG,"IS VISIBLE!");
else if(ivSelectedImage.getVisibility() == View.GONE)
Log.i(TAG,"IS GONE!");
else if(ivSelectedImage.getVisibility() == View.INVISIBLE)
Log.i(TAG,"IS INVISIBLE!");
and this prints in my console "IS VISIBLE"!
BRIEFLY: If I set GONE in the XML, and then I set VISIBLE (programmatically) getHeight() and getWidth() can't get the correct value (also if when I call these methods the View is actually VISIBLE).
While, If I set VISIBLE in the XML, the methods getHeight() and getWidth() return me the correct values.

You don't need to use the view size at runtime for this example. Based on your code, while the view visibility is set to gone the main container, your LinearLayout, as a fixed height of 300dp. As a result, you already know one of the dimensions of your view since at best android:layout_height="match_parent" can only be equal to 300dp.
To scale properly you just need the screen width - since your main view (and nested RelativeLayout and ImageView are also set to match_parent). If you're in an activity use this
Display display = getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
int width = size.x;
otherwise you can get the display using
WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
Display display = wm.getDefaultDisplay();
Just run this calculation before you need the set the image. Store the results to SharedPreferences or something and then use that ratio the 300dp height and screen width to scale the image.

Image Gallery with a Horizontal Scrollview

I´m trying to do an easy example of an image gallery using horizontalscrollview and adding the images dynamically. I have searched examples but most are too complex. Is there a simple example of how to do it?

Here is some simple example which has implemented horizontal scroll view to look like image gallery
this will help you
Add HorizontalScrollView in layout:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<HorizontalScrollView
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<LinearLayout
android:id="#+id/mygallery"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal"
/>
</HorizontalScrollView>
</LinearLayout>
Main Java code:
package com.example.androidhorizontalscrollviewgallery;
import java.io.File;
import android.os.Bundle;
import android.os.Environment;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup.LayoutParams;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.Toast;
public class MainActivity extends Activity {
LinearLayout myGallery;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
myGallery = (LinearLayout)findViewById(R.id.mygallery);
String ExternalStorageDirectoryPath = Environment
.getExternalStorageDirectory()
.getAbsolutePath();
String targetPath = ExternalStorageDirectoryPath + "/test/";
Toast.makeText(getApplicationContext(), targetPath, Toast.LENGTH_LONG).show();
File targetDirector = new File(targetPath);
File[] files = targetDirector.listFiles();
for (File file : files){
myGallery.addView(insertPhoto(file.getAbsolutePath()));
}
}
View insertPhoto(String path){
Bitmap bm = decodeSampledBitmapFromUri(path, 220, 220);
LinearLayout layout = new LinearLayout(getApplicationContext());
layout.setLayoutParams(new LayoutParams(250, 250));
layout.setGravity(Gravity.CENTER);
ImageView imageView = new ImageView(getApplicationContext());
imageView.setLayoutParams(new LayoutParams(220, 220));
imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
imageView.setImageBitmap(bm);
layout.addView(imageView);
return layout;
}
public Bitmap decodeSampledBitmapFromUri(String path, int reqWidth, int reqHeight) {
Bitmap bm = null;
// First decode with inJustDecodeBounds=true to check dimensions
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(path, options);
// Calculate inSampleSize
options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);
// Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;
bm = BitmapFactory.decodeFile(path, options);
return bm;
}
public 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;
}
}
Note: in this example, the bitmaps in HorizontalScrollView will not be removed even not in screen. So if too much bitmaps loaded, error of java.lang.OutOfMemoryError will be thrown!

You could create a div and set the overflow to hidden then nest another inside it which has the heights or widths of all the images depends on your animation you want horizontal so go with the width times by the amount of images and remember to include the margins in this. You then code a jQuery animate to run on the larger div which will move it to the left or right again depending on your preference
eg $('pic').animate({left:'_____ <- enter width of single image together with margin here ' +'px','slow' <-- whatever speed you prefer);
and then play with it from there. your handler can be able to click on another button or on the image... preference again. It's very flexible without much coding , it's not the best option for use. If that doesn't suit you then create an array of images and loop through them rather than use those specific dimensions to scroll. Best of luck with this. Hope I have helped you out.

android - display image from gallery

I have several images stored in content://media/external/images/media. I would like to display by using ImageView and add the image view to the table. here is my code.
BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = 24;
final Bitmap b = BitmapFactory.decodeFile("content://media"+getFileLocation(), options);
ImageView milestoneImageView = new ImageView(this);
milestoneImageView.setImageBitmap(b);
recordRow.addView(milestoneImageView);
When I print out the getFileLocation(), it says "/external/images/media/62". So I added "content://media" to make a full path, but it is not working...
Can someone point out why the code above is not working?

I think "/external/images/media/62" its a Uri not a real file path..
So instead of
final Bitmap b = BitmapFactory.decodeFile("content://media"+getFileLocation(), options);
Just try
final Bitmap b = BitmapFactory.decodeStream(getContentResolver().openInputStream("content://media"+getFileLocation()), null,options);
And let me know what happen..

Android - how to compress or downsize an image?

ImageButton avatarButton = (ImageButton) findViewById(R.id.ImageButton_Avatar);
avatarButton.setImageResource(R.drawable.avatar);
strAvatarFilename = "Image.jpg";
final Uri imageUriToSaveCameraImageTo = Uri.fromFile(new File(Environment.getExternalStorageDirectory()+"/Folder/"+strAvatarFilename));
avatarButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Intent pictureIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
pictureIntent.putExtra( MediaStore.EXTRA_OUTPUT, imageUriToSaveCameraImageTo );
startActivityForResult(Intent.createChooser(pictureIntent, strAvatarPrompt), TAKE_AVATAR_CAMERA_REQUEST);
Editor editor = Preferences.edit();
editor.putString(PREFERENCES_AVATAR, imageUriToSaveCameraImageTo.getPath());
editor.commit();
}
});
I have this code. It takes a photo and then stores it in two locations, the default location on the SDcard and the /folder/ file i want the photo to be stored in also. Once taken i refresh the screen using this...
ImageButton avatarButton = (ImageButton) findViewById(R.id.ImageButton_Avatar);
String strAvatarUri = Preferences.getString(PREFERENCES_AVATAR, "");
Uri imageUri = Uri.parse(strAvatarUri);
avatarButton.setImageURI(null);
avatarButton.setImageURI(imageUri);
This refreshes the image button so the user can see the image they have taken. However, this is appears very big and fills the screen. Is there any way i can compress or downsize the image so the user can see it at a reasonable size? thanks

Bitmap thumb = Bitmap.createScaledBitmap (BitmapFactory.decodeFile(photoPath), 96, 96, false);
Where the second and third parameters to createScaledBitmap are the width and height respectively.
http://developer.android.com/reference/android/graphics/Bitmap.html#createScaledBitmap%28android.graphics.Bitmap,%20int,%20int,%20boolean%29
EDIT: It now occurred to me that you can do this in a faster, more efficient way, using BitmapFactory.Options and the inSampleSize option:
BitmapFactory.Options opts = new BitmapFactory.Options ();
opts.inSampleSize = 2; // for 1/2 the image to be loaded
Bitmap thumb = Bitmap.createScaledBitmap (BitmapFactory.decodeFile(photoPath, opts), 96, 96, false);
This way you will save even more memory and the downsizing should take less time.

You can mess with the ImageButton's scaleType properties (to fitXY for example, or cropCenter), and by setting a fixed size to LayoutPreferences (height and width) you'll be all set.

The Android Library SiliCompressor provide this functionality for you to compress your images while keeping the image quality.