My application is some kind of "mini paint" and I would like to save my current view to the device memory... I would like to do the the opposite process too (Load an image from the device memory and set it as my currentview)
MiniPaint
yeah that's suppose to be a flamingo, I'm an artist!
Haven't tried it myself, but this answer shows taking a screenshot programmatically by getting the root view and saving off its drawing cache. That may be all you need to save your painting.
EDIT: Fixed link
First off I am assuming you are performing this drawing by overriding the onDraw() method on a View object, which passes in a Canvas object that you then perform some drawing operations on.
Here's a very basic way to approach this problem. There are probably lots of additional considerations to take into account, such as the file format(s) you read from and write to, and some extra error handling in the I/O code. But this should get you going.
To save what drawing you currently have, write out your View's drawingCache to a Picture object, then use the Picture's writeToStream method.
To load a pre-existing picture, you can use the Picture.readFromStream method, then in your onDraw call, draw the loaded picture to your Canvas.
To Wit:
/**
* Saves the current drawing cache of this View object to external storage.
* #param filename a file to be created in the device's Picture directory on the SD card
*/
public void SaveImage(String filename) {
// Grab a bitmap of what you've drawn to this View object so far
Bitmap b = this.getDrawingCache();
// It's easy to save a Picture object to disk, so we copy the contents
// of the Bitmap into a Picture
Picture pictureToSave = new Picture();
// To copy the Bitmap into the Picture, we have to use a Canvas
Canvas c = pictureToSave.beginRecording(b.getWidth(), b.getHeight());
c.drawBitmap(b, 0, 0, new Paint());
pictureToSave.endRecording();
// Create a File object where we are going to write the Picture to
File file = new File(this.getContext().getExternalFilesDir(Environment.DIRECTORY_PICTURES), filename);
try {
file.createNewFile();
}
catch (IOException ioe) {
ioe.printStackTrace();
}
// Write the contents of the Picture object to disk
try {
OutputStream os = new FileOutputStream(file);
pictureToSave.writeToStream(os);
os.close();
}
catch (FileNotFoundException fnfe) {
fnfe.printStackTrace();
}
}
/**
* Returns a Picture object loaded from external storage
* #param filename the name of the file in the Pictures directory on the SD card
* #return null if the file is not found, or a Picture object.
*/
public Picture LoadImage(String filename) {
// Load a File object where we are going to read the Picture from
File file = new File(this.getContext().getExternalFilesDir(Environment.DIRECTORY_PICTURES), filename);
Picture pictureToLoad = null;
try {
InputStream is = new FileInputStream(file);
pictureToLoad = Picture.createFromStream(is);
is.close();
}
catch (FileNotFoundException fnfe) {
fnfe.printStackTrace();
}
// Return the picture we just loaded. Draw the picture to canvas using the
// Canvas.draw(Picture) method in your View.onDraw(Canvas) method
return pictureToLoad;
}
Useful links I read to figure this out:
Reference on generating file paths in the device's external storage
Picture
Canvas
Bitmap
Related
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
Im new to android development and trying to get metadata of image using ExifInterface. I stored the image under drawable and trying to get the metadata but getting null values for all fields(date, imagelength, imagewidth). I tried to access image path as this :
String path = "drawable://" + R.drawable.testimage;
and provided this path to ExifInterface.
ExifInterface exif = new ExifInterface(path);
I dont know if storing image under drawable is correct or not because when I run the app in emulator I get something like this :
E/JHEAD﹕ can't open 'drawable://2130837561'
So if this is wrong then please tell me where should I store the image and how to provide image path to ExifInterface.
Thank you in advance.
To get a drawable, you can you this snippet:
Drawable drawable = getResources().getDrawable(android.R.drawable.your_drawable);
I'm not sure if your way is correct, as I've never seen it like that. Do you really need the path to your image to use it on that ExifInterface class?
Ok, I did some digging and found this question, which led me to this one. As it seems, you can not get an absolute path from a resource inside your apk. A good solution would be for you to save it as a file on the external memory, and then you can get the path you want.
First of all, add this to your AndroidManifest.xml, so your app can write to the cellphone memory:
<uses-permission
android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
Ok, to save it you can try this, first create a bitmap from your drawable resource:
Bitmap bitmap = BitmapFactory.decodeResource(getResources(),R.drawable.your_drawable);
After that get the path you want to save your images, and put it on a String. More info on that here.
The Android docs have a good example on how to get the path. You can see it here.
To keep it simple, I'll copy and paste the snippet from the docs.
void createExternalStoragePrivateFile() {
// Create a path where we will place our private file on external
// storage.
File file = new File(getExternalFilesDir(null), "DemoFile.jpg");
try {
// Very simple code to copy a picture from the application's
// resource into the external file. Note that this code does
// no error checking, and assumes the picture is small (does not
// try to copy it in chunks). Note that if external storage is
// not currently mounted this will silently fail.
InputStream is = getResources().openRawResource(R.drawable.balloons);
OutputStream os = new FileOutputStream(file);
byte[] data = new byte[is.available()];
is.read(data);
os.write(data);
is.close();
os.close();
} catch (IOException e) {
// Unable to create file, likely because external storage is
// not currently mounted.
Log.w("ExternalStorage", "Error writing " + file, e);
}
}
void deleteExternalStoragePrivateFile() {
// Get path for the file on external storage. If external
// storage is not currently mounted this will fail.
File file = new File(getExternalFilesDir(null), "DemoFile.jpg");
if (file != null) {
file.delete();
}
}
boolean hasExternalStoragePrivateFile() {
// Get path for the file on external storage. If external
// storage is not currently mounted this will fail.
File file = new File(getExternalFilesDir(null), "DemoFile.jpg");
if (file != null) {
return file.exists();
}
return false;
}
After that, get the path of the file you saved on the external memory, and do as you wish.
I'll keep the old example as well. You can use the method getExternalStorageDirectory() to get the path, or getExternalCacheDir(). After that, you can use File method called getAbsolutePath() to get your String.
String path = (...) // (you can choose where to save here.)
File file = new File(path, "your_drawable.png");
FileOutputStream out = new FileOutputStream(file);
bitmap.compress(Bitmap.CompressFormat.PNG, 100, out); // You can change the quality from 0 to 100 here, and the format of the file. It can be PNG, JPEG or WEBP.
out.flush();
out.close();
For more info on the Bitmap class, check the docs.
If you need more info, let me know and I'll try to show more samples.
EDIT: I saw your link, and there was this snippet there:
//change with the filename & location of your photo file
String filename = "/sdcard/DSC_3509.JPG";
try {
ExifInterface exif = new ExifInterface(filename);
ShowExif(exif);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
Toast.makeText(this, "Error!",
Toast.LENGTH_LONG).show();
}
As you can see, if you really want to see the exif data of a internal image resource, you'll have to save it somewhere else, and then you can try to get the absolute path for that File, then, call the method to show the exif.
I have created an Android Invoice app. The generated invoice is standard Android layout with nested views. I am looking for a library that I can use to convert this view to an pdf document.
I am surprised there is no straight forward option coming up in my search or Perhaps I have the done the first thing last. Or perhaps what I am looking for is not possible.
Would someone please help point me to a tool that will help me convert or generate a PDF from an Android view. I am open to free and modest paid option. Or let me know is if what I am looking for is not possible.
Take a screen at your device:
Bitmap screen;
View v1 = MyView.getRootView();
v1.setDrawingCacheEnabled(true);
screen= Bitmap.createBitmap(v1.getDrawingCache());
v1.setDrawingCacheEnabled(false);
If you're having ScrollView as root view then:
LayoutInflater inflater = (LayoutInflater) this.getSystemService(LAYOUT_INFLATER_SERVICE);
RelativeLayout root = (RelativeLayout) inflater.inflate(R.layout.activity_main, null); //RelativeLayout is root view of my UI(xml) file.
root.setDrawingCacheEnabled(true);
Bitmap screen= getBitmapFromView(this.getWindow().findViewById(R.id.relativelayout)); // here give id of our root layout (here its my RelativeLayout's id)
Here is the getBitmapFromView() method:
public static Bitmap getBitmapFromView(View view) {
//Define a bitmap with the same size as the view
Bitmap returnedBitmap = Bitmap.createBitmap(view.getWidth(), view.getHeight(),Bitmap.Config.ARGB_8888);
//Bind a canvas to it
Canvas canvas = new Canvas(returnedBitmap);
//Get the view's background
Drawable bgDrawable =view.getBackground();
if (bgDrawable!=null)
//has background drawable, then draw it on the canvas
bgDrawable.draw(canvas);
else
//does not have background drawable, then draw white background on the canvas
canvas.drawColor(Color.WHITE);
// draw the view on the canvas
view.draw(canvas);
//return the bitmap
return returnedBitmap;
}
It will display entire screen including content hidden in your ScrollView.
Now that we have our bitmap screen let's save it to pdf (you have to download itextpdf-5.3.2.jar file and attach in your project..)
private static String FILE = "mnt/sdcard/invoice.pdf"; // add permission in your manifest...
try
{
Document document = new Document();
PdfWriter.getInstance(document, new FileOutputStream(FILE));
document.open();
ByteArrayOutputStream stream = new ByteArrayOutputStream();
screen.compress(Bitmap.CompressFormat.PNG, 100, stream);
byte[] byteArray = stream.toByteArray();
addImage(document,byteArray);
document.close();
}
catch (Exception e)
{
e.printStackTrace();
}
private static void addImage(Document document,byte[] byteArray)
{
try
{
image = Image.getInstance(byteArray);
}
catch (BadElementException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
catch (MalformedURLException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
// image.scaleAbsolute(150f, 150f);
try
{
document.add(image);
} catch (DocumentException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
Haven't tested anything. Here are all the sources I used: source1, source2, source3.
You can use a custom library such as https://github.com/HendrixString/Android-PdfMyXml. I prefer this library than any other method. Just Go through these.
but there is another way - How to convert Android View to PDF - that generate a pdf that contains bitmap of your layout
I made a library to achieve this objective (Getting PDF from Java View objects).
The main code snippet is -
PdfGenerator.getBuilder()
.setContext(context)
.fromViewSource()
.fromView(targetView) /* "targetView" is the view ,you want to convert PDF */
/* "fromLayoutXML()" takes array of layout resources.
* You can also invoke "fromLayoutXMLList()" method here which takes list of layout resources instead of array. */
.setDefaultPageSize(PdfGenerator.PageSize.A4)
/* It takes default page size like A4,A5. You can also set custom page size in pixel
* by calling ".setCustomPageSize(int widthInPX, int heightInPX)" here. */
.setFileName("Test-PDF")
/* It is file name */
.setFolderName("FolderA/FolderB/FolderC")
/* It is folder name. If you set the folder name like this pattern (FolderA/FolderB/FolderC), then
* FolderA creates first.Then FolderB inside FolderB and also FolderC inside the FolderB and finally
* the pdf file named "Test-PDF.pdf" will be store inside the FolderB. */
.openPDFafterGeneration(true)
/* It true then the generated pdf will be shown after generated. */
.build(new PdfGeneratorListener() {
#Override
public void onFailure(FailureResponse failureResponse) {
super.onFailure(failureResponse);
/* If pdf is not generated by an error then you will findout the reason behind it
* from this FailureResponse. */
}
#Override
public void showLog(String log) {
super.showLog(log);
/*It shows logs of events inside the pdf generation process*/
}
#Override
public void onSuccess(SuccessResponse response) {
super.onSuccess(response);
/* If PDF is generated successfully then you will find SuccessResponse
* which holds the PdfDocument,File and path (where generated pdf is stored)*/
}
});
Without using a third-party library you can use PdfDocument which was introduced in Android API 19. However, keep in mind that the dimension of the pdf file will be in the postscript point(1/72 inch). Therefore, you have to convert your view's dimension to match the requirement before drawing to the canvas.
I have a folder with a few images, these images are added by user dynamically. So i need to get the R.drawable ID's of these images in android.... ???
Where are you saving these images too? When images are being added dynamically at runtime usually you need to store them on the phones storage. If you want the images to be stored in the external storage (SDCard) then you can use the following code to retrieve them and add them to your view (Which I assume your doing). This code assumes the images are being stored to your devices SDCard, which is where they will be pulled from.
//Get root directory of storage directory, pass in the name of the Folder if they are being stored farther down, i.e getExternalFilesDir("FolderName/FolderName2")
String state = Environment.getExternalStorageState();
if (Environment.MEDIA_MOUNTED.equals(state)) {
// We can read and write the media
File dir = getExternalFilesDir(null);
Bitmap bmap = null;
try {
InputStream is = new FileInputStream(new File(dir,"image.jpg"));
bmap = BitmapFactory.decodeStream(is);
} catch (FileNotFoundException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
if (bmap!=null) {
ImageView view = new ImageView(this);
view.setImageBitmap(bmap);
}
}
I'm saving an image from the device's camera to a directory on the SD card (ex: /sdcard/appName/image.jpg), then I save the path into a database. My problem is that I can't seem to load the images into a ListView with a cursor adapter.
I tried the following code, where helper.getImg(); is a method from my database helper that returns a String (the file path), but it is not working.
icon=(ImageView)row.findViewById(R.id.icon_pura);
String imgPath=helper.getImg(c);
Bitmap myBitmap=BitmapFactory.decodeFile(imgPath);
icon.setImageBitmap(myBitmap);
the answer has to do with URIs, and you need to use the externalstorage() function. Using set paths won't work on every device
anyway you store path into the URI which is more flexible for retrieving and parsings items at that path
String filepath = Environment.getExternalStorageDirectory().getAbsolutePath()+"/Directory name/";
File file = new File(filepath,imagename);
FileInputStream fs = null;
try
{
fs = new FileInputStream(file);
}
catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
BitmapFactory.Options bfOptions = new BitmapFactory.Options();
/*
* bfOptions.inDither=false; //Disable Dithering mode
* bfOptions.inPurgeable=true; //Tell to gc that whether it needs
* free memory, the Bitmap can be cleared
* bfOptions.inInputShareable=true;*/
bfOptions.inJustDecodeBounds = false;
bfOptions.inTempStorage = new byte[32 * 1024];
try {
Bitmap originalImage = BitmapFactory.decodeFileDescriptor(fs.getFD(), null,bfOptions);
icon.setImageBitmap(originalImage);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
If you follow himanshu's (correct) advice, make sure that if you're going to allow the user the option of loading and re-loading the image, make sure to manually icon.setImageBitmap(null); between loads, because otherwise Android will leak that memory and you'll crash your app. It's not 100% consistant, and has something to do with the sizes of the images you're loading, but I just found this leak a few days ago and am 100% certain that it's there.