Is it possible to show previously downloaded image in Glide as placeholder while downloading new image.
Like I have an image loaded in imageview using glide. Now the imageurl is changed, so while loading this new image is it possible to keep displaying the old image (might be from cache).
What I want is while the new image is being loaded from the URL, is it possible to keep the current image as placeholder.
I found the answer to this in the discussion here - https://github.com/bumptech/glide/issues/527#issuecomment-148840717.
Intuitively I also thought of using placeholder(), but the problem is that as soon as you load the second image, you loose the reference to the first one. You can still reference it but it is not safe as it may be reused by Glide or recycled.
The proposed solution from the discussion is to use thumbnail() and load the first image again. The load will return the first image immediately from the memory cache and it will look as if the image did not change until the second image is loaded:
String currentImageUrl = ...;
String newImageUrl = ...;
Glide.with(this)
.load(newImageUrl)
.thumbnail(Glide.with(this)
.load(currentImageUrl)
.fitCenter()
)
.fitCenter()
.into(imageView);
Glide have a capability of getting the bitmap of the image from that url, so just get it and then save it to a desired storage into your phone, and after that in your .placeholder() just use that bitmap when you are trying to get another image , take a look at this snippet
/** Download the image using Glide **/
Bitmap theBitmap = null;
theBitmap = Glide.
with(YourActivity.this).
asBitmap().
load("Url of your image").
into(-1, -1).
get(); //with this we get the bitmap of that url
saveToInternalStorage(theBitmap, getApplicationContext(), "your preferred image name");
/** Save it on your device **/
public String saveToInternalStorage(Bitmap bitmapImage, Context context, String name){
ContextWrapper cw = new ContextWrapper(context);
// path to /data/data/yourapp/app_data/imageDir
String name_="foldername"; //Folder name in device android/data/
File directory = cw.getDir(name, Context.MODE_PRIVATE);
// Create imageDir
File mypath=new File(directory,name_);
FileOutputStream fos = null;
try {
fos = new FileOutputStream(mypath);
// Use the compress method on the BitMap object to write image to the OutputStream
bitmapImage.compress(Bitmap.CompressFormat.PNG, 100, fos);
fos.close();
} catch (Exception e) {
e.printStackTrace();
}
Log.e("absolutepath ", directory.getAbsolutePath());
return directory.getAbsolutePath();
}
/** Method to retrieve image from your device **/
public Bitmap loadImageFromStorage(String path, String name)
{
Bitmap b;
String name_= name; //your folderName
try {
File f=new File(path, name_);
b = BitmapFactory.decodeStream(new FileInputStream(f));
return b;
}
catch (FileNotFoundException e)
{
e.printStackTrace();
}
return null;
}
/** Retrieve your image from device and set to imageview **/
//Provide your image path and name of the image your previously used.
Bitmap b= loadImageFromStorage(String path, String name)
ImageView img=(ImageView)findViewById(R.id.your_image_id);
img.setImageBitmap(b);
Related
I'm workin with Volley API in my WebServices, and then I'll write the data in with SQLITE.
Webservices that comes with a JSON with many itens, each of then has data and a image, and I need to keep this image in my cache to display offline in a ListView and later on a detail screen. In the future the user will clean these itens and clear the imagens of them too.
Well, how can I save these images in my local DB and link with each Item that I have from the JSON?
I will be, in 90% of the time, offline. I will only stay online for synchronizing and download the updated server items.
For dealing with images in Android the benchmark is to use Picasso library. It takes care of:
Handling ImageView recycling and download cancelation in an adapter;
Complex image transformations with minimal memory use;
Automatic memory and disk caching.
Besides that, if you're going to display images in lists and need animation to enhance your UI, I strongly recommend changing from ListView to RecyclerView. It is not recommended to store the images in the DB, you would lose time converting this from/to blobs (check here and here). Said that, what I suggest is:
Use Picasso to load the images from the URL provided in the JSON;
Implement a Custom target to handle the image file downloaded by Picasso;
Save the image in a folder inside your app directory;
Use RecyclerView to display the images; (optional)
If you need a project example where those things are done, you can check this. In this project I follow the approache I've described above. You can download the app from the store and see how it will download the images.
Quicky-guide:
To use Picasso add this to you module's gradle file: compile 'com.squareup.picasso:picasso:2.5.2'
Create a class that implements import com.squareup.picasso.Callback;:
public class ImageWarehouse implements Callback {
private static final String TAG = "ImageWarehouse";
private String mDirectory;
private String mFileName;
private ImageView mContainer;
#Inject
App mApplication;
public ImageWarehouse(String fileName, ImageView container, String directory) {
this.mFileName = fileName;
this.mContainer = container;
this.mDirectory = directory;
this.getStorageDir();
}
#Override
public void onSuccess() {
if (this.isExternalStorageWritable()) {
final Bitmap bitmap = ((BitmapDrawable) this.mContainer.getDrawable()).getBitmap();
new AsyncTask<Void, Void, File>() {
#Override
protected File doInBackground(Void... params) {
File file = null;
try {
file = new File(ImageWarehouse.this.getStorageDir().getPath().concat("/").concat(ImageWarehouse.this.mFileName.concat(Constants.MEDIA_EXTENSION)));
file.createNewFile();
FileOutputStream ostream = new FileOutputStream(file);
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, ostream);
ostream.close();
} catch (Exception e) {
Log.e(TAG, "External Storage is not available");
}
return file;
}
}.execute();
} else {
Log.e(TAG, "External Storage is not available");
}
}
#Override
public void onError() {
}
public boolean isExternalStorageWritable() {
String state = Environment.getExternalStorageState();
if (Environment.MEDIA_MOUNTED.equals(state)) {
return true;
}
return false;
}
public File getStorageDir() {
File file = new File(Environment.getExternalStorageDirectory(), Constants.MEDIA_DIRECTORY.concat(this.mDirectory));
if (!file.mkdirs()) {
}
return file;
}
}
Call Picasso in order to display the image in the layout and save it to the specified path:
Picasso
.load(URL)
.fit()
.centerCrop()
.into(viewHolder.cover,
new ImageWarehouse(
name,
viewHolder.cover,
Constants.MEDIA_CHARACTER
)
);
You can user Android-Universal-Image-Loader it is also cache image in memory. it is show from cache when next time same url used in imageloader for get image
see below link for complete source code of Universal Image Loader Example.
Android - Universal Image Loader
You can save your images in Sqlite as blob and can retrieve it when required. Create table as
create table sometable(id integer primary key autoincrement,photo BLOB);
And save the image as
//convert image into byte[]
ByteArrayOutputStream baos = new ByteArrayOutputStream();
Bitmap bitmap = ((BitmapDrawable)getResources().getDrawable(R.drawable.common)).getBitmap();
bitmap.compress(Bitmap.CompressFormat.PNG, 100, baos);
byte[] photo = baos.toByteArray();
//And now store this image
ContentValues initialValues = new ContentValues();
initialValues.put("photo",photo);
return db.insert("sometable", null, initialValues);
And retrieve image as
Cursor cur=your query;
while(cur.moveToNext())
{
byte[] photo=cur.getBlob(index of blob cloumn);
}
I'm working on a school android project.
I need to have a download button which downloads a picture(when we have class)
And after display it in another activity(even in offline mode, and after quiting)
I've tried picasso, but I can't get it to save and use it in offline mode.
For you to support offline mode, You need to Save the image on your disk because when your cache is cleared, The image is cleared as well.
You can easily use Glide to Solve this, also storing on device and retrieving
You can Learn more about Glide here http://inthecheesefactory.com/blog/get-to-know-glide-recommended-by-google/en
/** Download the image using Glide **/
Bitmap theBitmap = null;
theBitmap = Glide.
with(YourActivity.this).
load("Url of your image").
asBitmap().
into(-1, -1).
get();
saveToInternalStorage(theBitmap, getApplicationContext(), "your preferred image name");
/** Save it on your device **/
public String saveToInternalStorage(Bitmap bitmapImage, Context context, String name){
ContextWrapper cw = new ContextWrapper(context);
// path to /data/data/yourapp/app_data/imageDir
String name_="foldername"; //Folder name in device android/data/
File directory = cw.getDir(name_, Context.MODE_PRIVATE);
// Create imageDir
File mypath=new File(directory,name);
FileOutputStream fos = null;
try {
fos = new FileOutputStream(mypath);
// Use the compress method on the BitMap object to write image to the OutputStream
bitmapImage.compress(Bitmap.CompressFormat.PNG, 100, fos);
fos.close();
} catch (Exception e) {
e.printStackTrace();
}
Log.e("absolutepath ", directory.getAbsolutePath());
return directory.getAbsolutePath();
}
/** Method to retrieve image from your device **/
public Bitmap loadImageFromStorage(String path, String name)
{
Bitmap b;
String name_="foldername";
try {
File f=new File(path, name_);
b = BitmapFactory.decodeStream(new FileInputStream(f));
return b;
}
catch (FileNotFoundException e)
{
e.printStackTrace();
}
return null;
}
/** Retrieve your image from device and set to imageview **/
//Provide your image path and name of the image your previously used.
Bitmap b= loadImageFromStorage(String path, String name)
ImageView img=(ImageView)findViewById(R.id.your_image_id);
img.setImageBitmap(b);
Thanks to #Droidman :
How to download and save an image in Android
Of course you can perform downloading and managing images by yourself,
but if your project is quite complex already, there are a lot of
libraries around and you do not need to reinvent the wheel. I won't
post code this time since there are a lot of examples, but I'm going
to tell you about 2 most useful libraries (IMO) related to image
downloading.
1) Android Volley. A powerful networking library created by Google and
covered by official documentation. POST'ing or GET'ing data, images,
JSON - volley will manage it for you. Using volley just for image
downloading is a bit of an overkill in my opinion.
2) Picasso
Image downloading and caching, perfect for
ListView/GridView/RecyclerView. Apache 2.0 license.
3) Fresco
Quite a new image loading library created by Facebook. Progressive
JPEG streaming, gifs and more. Apache 2.0
You could use Android Library called Universal Image Loader:
https://github.com/nostra13/Android-Universal-Image-Loader
So I have the following code in an AsyncTask. The AsyncTask takes in a url to an image file, downloads it into a Bitmap, saves the Bitmap off to disk somewhere, and then displays the Bitmap in an existing ImageView.
Here's the implementation of the doInBackground() call for my AsyncTask:
protected Bitmap doInBackground(String... urls) {
try {
URL image_url = new URL(urls[0]);
String image_url_prefix_regex = "http://www\\.somewebsite\\.com";
if (externalStorageIsAvailable()) {
String file_path = getExternalFilesDir(null).getPath() + image_url.toString().replaceAll(image_url_prefix_regex, "");
File target_file = new File(file_path);
if (!target_file.getParentFile().exists()) {
target_file.getParentFile().mkdirs();
}
BitmapFactory.Options bitmap_options = new BitmapFactory.Options();
bitmap_options.inScaled = false;
bitmap_options.inDither = false;
bitmap_options.inPreferredConfig = Bitmap.Config.ARGB_8888;
bitmap_options.inPreferQualityOverSpeed = true;
bitmap_options.inSampleSize = 1;
Bitmap image = BitmapFactory.decodeStream(image_url.openStream(), null, bitmap_options);
image.compress(CompressFormat.JPEG, 100, new FileOutputStream(target_file));
return image;
}
}
catch (MalformedURLException e) {
Log.v(DEBUG_TAG, "Error: Caught MalformedURLException");
}
catch (IOException e) {
Log.v(DEBUG_TAG, "Error: Caught IOException");
}
return null;
}
Then later in the onPostExecute() call I have this:
protected void onPostExecute(Bitmap image) {
ImageView mImageView = (ImageView) findViewById(R.id.main_image);
mImageView.setImageBitmap(image);
}
Yet when the code downloads and displays the image, the image is reduced in size and quality. How do I make it so that the resulting image is full quality? Those BitmapFactory.Options settings are the things I've tried thus far, but they did not seem to work.
Note that I'm not asking about the image that gets saved to external storage. I think that one will likely be of lower quality due to getting compressed again, but that shouldn't affect the image I'm sending to my ImageView, which is what I'm asking about. Of course, if there's anything wrong with these assumptions please point them out.
Why you are using Bitmap factory options while decoding bitmap Stream ?
Just use the
Bitmap image = BitmapFactory.decodeStream(image_url.openStream());
instead of
Bitmap image = BitmapFactory.decodeStream(image_url.openStream(), null, bitmap_options);
I have an application that uses a canvas function, I want to save and retrieve all images (whatever I saved).?
issues
I can save and retrieve the single image only
Dynamically I save the image,(image001,image002......)
update
try {
toDisk.compress(Bitmap.CompressFormat.JPEG, 100, new FileOutputStream(new File("/mnt/sdcard/image00"+saveimageid+".jpg")));
saveimageid++;
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
I retrieve the image from image001.
File imgFile = new File("/mnt/sdcard/image001.jpg");
if(imgFile.exists()){
Bitmap myBitmap = BitmapFactory.decodeFile(imgFile.getAbsolutePath());
ImageView myImage = (ImageView) findViewById(R.id.ImageView01);
myImage.setImageBitmap(myBitmap);
I'm guessing you want to load all the files that match imageXYZ.jpg.
I have no idea why you save the files like "00"+saveimageid+".jpg.
If you want to make sure the filename is equally long (or at least three positions) do something like
new File(String.format("/mnt/sdcard/image%03d.jpg", saveimageId))
To retrieve the files you might
File dir = new File("/mnt/sdcard/");
File[] images = dir.listFiles(new FilenameFilter() {
#Override
public boolean accept(final File dir, final String filename) {
return filename.matches("image[0-9]+\\.jpg");
}
});
Then you can use the images array however you please.
As a sidenote: If this is Android you should not assume that external storage is placed in /mnt/sdcard. Use Environment.getExternalStorageDirectory()
I am trying to use an image from the sd card and set it as the background for a relativelayout. I have tried other solutions that i have found here and elsewhere but they havent seemed to work for me. here is my code. I have commented out other ways that i have tried and didnt work. the only thing that worked for me was using setBackgroudnResource and using a resource from the app, but this was just to test to make sure mRoot was set up correctly. when I have tried all the other ways, it just doesn't set anything. Anyone know what I am doing wrong, or if there is a better way to do this?
//one way i tired...
//String extDir = Environment.getExternalStorageDirectory().toString();
//Drawable d = Drawable.createFromPath(extDir + "/pic.png");
//mRoot.setBackgroundDrawable(d);
//another way tried..
//Drawable d = Drawable.createFromPath("/sdcard/pic.png");
//mRoot.setBackgroundDrawable(d);
//last way i tried...
mRoot.setBackgroundDrawable(Drawable.createFromPath(new File(Environment.getExternalStorageDirectory(), "pic.png").getAbsolutePath()));
//worked, only to verify mRoot was setup correctly and it could be changed
//mRoot.setBackgroundResource(R.drawable.bkg);
You do not load a drawable from SD card but a bitmap. Here is a method to load it with the reduced sampling (quality) so the program will not complain if the image is too large. Then I guess you need to process this bitmap i.e. crop it and resize for the background.
// Read bitmap from Uri
public Bitmap readBitmap(Uri selectedImage) {
Bitmap bm = null;
BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = 2; //reduce quality
AssetFileDescriptor fileDescriptor =null;
try {
fileDescriptor = this.getContentResolver().openAssetFileDescriptor(selectedImage,"r");
} catch (FileNotFoundException e) {
e.printStackTrace();
}
finally{
try {
bm = BitmapFactory.decodeFileDescriptor(fileDescriptor.getFileDescriptor(), null, options);
fileDescriptor.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return bm;
}
The Uri here can be supplied from a gallery picker activity.
The image then can be saved into application resources and loaded into an imageView
private void saveBackground(Bitmap Background) {
String strBackgroundFilename = "background_custom.jpg";
try {
Background.compress(CompressFormat.JPEG, 80, openFileOutput(strBackgroundFilename, MODE_PRIVATE));
} catch (Exception e) {
Log.e(DEBUG_TAG, "Background compression and save failed.", e);
}
Uri imageUriToSaveCameraImageTo = Uri.fromFile(new File(BackgroundSettings.this.getFilesDir(), strBackgroundFilename));
// Load this image
Bitmap bitmapImage = BitmapFactory.decodeFile(imageUriToSaveCameraImageTo.getPath());
Drawable bgrImage = new BitmapDrawable(bitmapImage);
//show it in a view
ImageView backgroundView = (ImageView) findViewById(R.id.BackgroundImageView);
backgroundView.setImageURI(null);
backgroundView.setImageDrawable(bgrImage);
}
File file = new File( url.getAbsolutePath(), imageUrl);
if (file.exists()) {
mDrawable = Drawable.createFromPath(file.getAbsolutePath());
}
I suggest checking that the drawable is being loaded correctly. Some things to try:
Try using a different image on the sd card
Put pic.png in R.drawable and make sure mRoot.setBackgroundResource() does what you expect
After loading the drawable, check d.getBounds() to make sure it is what you expect