android

Read more about the article Chrome Custom Tabs Integration – SUSI.AI Android App

Chrome Custom Tabs Integration – SUSI.AI Android App

Earlier, we have seen the apps having external links that opens and navigates the user to the phone browser when clicked, then we came up with something called WebView for Android, but nowadays we have shifted to something called In-App browsers. The main drawback of the system/ phone browsers are they caused heavy transition. To overcome this drawback “Chrome Custom Tabs” were invented which allowed users to walk through the web content seamlessly.

SUSI.AI Android App earlier used the system browser to open any link present in the app.

This can be implemented easily by

Intent browserIntent = new Intent(Intent.ACTION_VIEW, Uri.parse(url));
startActivity(browserIntent);

This lead to a huge transition between the context of the app and the web browser.

Then, to reduce all the clutter Chrome Custom tabs by Google was evolved which drastically increased the loading speed and the heavy context switch was also not taking place due to the integration and adaptability of custom tabs within the app.

Chrome custom tabs also are very secured like Chrome Browser and uses the same feature and give developers a more control on the custom actions, user interface within the app.

                                comparing the load time of the above mentioned techniques

Ref : Android Dev – Chrome Custom Tabs

Integration of Chrome Custom Tabs

  • Adding the dependency in build.gradle(app-level) in the project
dependencies {
    //Other dependencies 
    compile 'com.android.support:customtabs:23.4.0'
}
  • Now instantiating a CustomTabsIntent Builder

    String url = “https://www.fossasia.org” // can be any link

CustomTabsIntent.Builder builder = new CustomTabsIntent.Builder(); //custom tabs intent builder

CustomTabsIntent customTabsIntent = builder.build();
  • We can also add animation or customize the color of the toolbar or add action buttons.

    builder.setColor(Color.RED) //for setting the color of the toolbar 
builder.setStartAnimations(this, R.anim.slide_in_right, R.anim.slide_out_left); //for start animation
builder.setExitAnimations(this, R.anim.slide_in_left, R.anim.slide_out_right); //for exit animation
  • Finally, we have have achieved everything with a little code. Final launch the web page

    Uri webpage = Uri.parse(url); //We have to pass an URI

customTabsIntent.launchUrl(context, webpage); //launching through custom tabs

Benefits of Chrome Custom Tabs

  1. UI Customization are easily available and can be implemented with very few lines of code. 
  2. Faster page loading and in-app access of the external link 
  3. Animations for start/exit  
  4. Has security and uses the same permission model as in chrome browser.

Resources

  1. Chrome Custom Tabs:  https://developer.chrome.com/multidevice/android/customtabs
  2. Chrome Custom Tabs Github Repo: GitHub – GoogleChrome/custom-tabs-client: Chrome custom tabs
  3. Android Blog: Android Developers Blog: Chrome custom tabs smooth the transition
  4. Video: Chrome Custom Tabs: Displaying 3rd party content in your Android

 

Continue ReadingChrome Custom Tabs Integration – SUSI.AI Android App
Read more about the article Building PSLab Android app with Fdroid

Building PSLab Android app with Fdroid

Fdroid is a place for open source enthusiasts and developers to host their Free and Open Source Software (FOSS) for free and get more people onboard into their community. Hosting an app in Fdroid is not a fairly easy process just like hosting one in Google Play. We need to perform a set of build checks prior to making a merge request (which is similar to pull request in GitHub) in the fdroid-data GitLab repository. PSLab Android app by FOSSASIA has undergone through all these checks and tests and now ready to be published.

Setting up the fdroid-server and fdroid-data repositories is one thing. Building our app using the tools provided by fdroid is another thing. It will involve quite a few steps to get started. Fdroid requires all the apps need to be built using:

$ fdroid build -v -l org.fossasia.pslab

 

This will output a set of logs which tell us what went wrong in the builds. The usual one in a first time app is obviously the build is not taking place at all. The reason is our metadata file needs to be changed to initiate a build.

Build:<versioncode>,<versionname>
    commit=<commit which has the build mentioned in versioncode>
    subdir=app
    gradle=yes

 

When a metadata file is initially created, this build is disabled by default and commit is set to “?”. We need to fill in those blanks. Once completed, it will look like the snippet above. There can be many blocks of “Build” can be added to the end of metadata file as we are advancing and upgrading through the app. As an example, the latest PSLab Android app has the following metadata “Build” block:

Build:1.1.5,7
    commit=0a50834ccf9264615d275a26feaf555db42eb4eb
    subdir=app
    gradle=yes

 

In case of an update, add another “Build” block and mention the version you want to appear on the Fdroid repository as follows:

Auto Update Mode:Version v%v
Update Check Mode:Tags
Current Version:1.1.5
Current Version Code:7

 

Once it is all filled, run the build command once again. If you have properly set the environment in your local PC, build will end successfully assuming there were no Java or any other language syntax errors.

It is worth to mention few other facts which are common to Android software projects. Usually the source code is packed in a folder named “app” inside the repository and this is the common scenario if Android Studio builds up the project from scratch. If this “app” folder is one level below the root, that is “android/app”, the build instructions shown above will throw an error as it cannot find the project files.

The reason behind this is we have mentioned “subdir=app” in the metadata file. Change this to “subdir=android/app” and run the build again. The idea is to direct the build to find where the project files are.

Apart from that, the commit can be represented by a tag instead of a long commit hash. As an example, if we had merge commits in PSLab labeled as “v.<versioncode>”, we can simply use “commit=v.1.1.5” instead of the hash code. It is just a matter of readability.

Happy Coding!

Reference:

  1. Metadata : https://f-droid.org/docs/Build_Metadata_Reference/#Build
  2. PSLab Android app Fdroid : https://gitlab.com/fdroid/fdroiddata/merge_requests/3271/diffs
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Read more about the article Handling Click Events using Custom Binding Adapters

Handling Click Events using Custom Binding Adapters

The Open Event Organiser Android App is the Event management app for organizers using the Open Event Platform. It is currently released in the Alpha phase on the Google Play Store here and is being actively developed by the community.

The Data Binding Library is one of the most popular libraries among the android developers. We use it extensively in the application in order to greatly simplify the UI binding logic. While trying to show the details of a speaker in the application, we wanted to list his/her social media links using Image buttons.

Upon clicking one of these buttons, the user was supposed to be directed to the link after opening the default web browser. This blog post discusses how we used custom Binding Adapters to handle click events on an Image Button by defining a custom attribute.

Defining the Binding Adapter

We defined a simple Binding Adapter for an Image button meant to handle social media links. We used “imageOnClick” as the custom attribute name for specifying the URL that will be opened once the button is clicked.

@BindingAdapter("imageOnClick")
public static void bindOnImageButtonClickListener(ImageButton imageButton, String url) {
  imageButton.setOnClickListener(view -> {
    if (url != null) {
      Context context = imageButton.getContext();
      Intent intent = new Intent(Intent.ACTION_VIEW);
      intent.setData(Uri.parse(url));
      if (intent.resolveActivity(context.getPackageManager()) != null) {
        context.startActivity(intent);
      } else {
        Toast.makeText(context, "No Web browser found", Toast.LENGTH_SHORT).show();
      }
    }
  });
}

 

The method can be named anything you want and can be placed anywhere in the project but we would recommend creating a separate class for all the Binding adapters.
The important things to take away from the above method are:

  • The method needs to be public otherwise the Data binding framework won’t be able to find it.
  • We need to pass in the view as the first parameter and the attribute value as the second parameter.

Then we simply set the familiar click listener to handle the click interaction. We use the Context from the view passed in the method as the first parameter. Then we create an Intent and set the passed in URL as the data. We make sure that the user has a browser installed on his/her android phone before we try to open the browser. We show a suitable error message if they don’t.

Using it in Layout

Using the custom attribute in the layout was extremely simple. We specified the url using the attribute “imageOnClick” and the rest was handled by the Binding Adapter and the Data binding framework.  

<ImageButton
     android:id="@+id/action_speakers_linkedin"
     android:layout_width="@dimen/spacing_larger"
     android:layout_height="match_parent"
     android:contentDescription="@string/linkedin_icon"
     app:imageOnClick="@{ speaker.linkedin }"
     android:background="#ededed"
     android:visibility="@{ (speaker.linkedin != null) ? View.VISIBLE : View.GONE }"
     app:srcCompat="@drawable/ic_linkedin_colored"/>

References

Continue ReadingHandling Click Events using Custom Binding Adapters
Read more about the article Implementing Filters in Phimp.me Android App

Implementing Filters in Phimp.me Android App

Image filters in phimp.me android app are implemented using the OpenCV library that enables the android developers to write code in C++/C which is compatible with java. I have implemented around eight filters in the filters.cpp file, mainly dealing with the colour variations that took place between the images.

Suppose that the color model used in consideration is the RGB (Red,Green,Blue) model and we define that every pixel is defined using these values. If we simply want to boost or focus on the red part of the image it can be done by enhancing the particular color in the source image i.e. modifying each pixel of the app by enhancing the blue color of each pixel. The code for the same can be written as :

void applyBlueBoostEffect(cv::Mat &src, cv::Mat &dst, int val) {
register int x, y;
float opacity = val * 0.01f;
cvtColor(src, src, CV_BGRA2BGR);
dst = Mat::zeros(src.size(), src.type());
uchar r, g, b,val1;

for (y = 0; y < src.rows; y++) {
for (x = 0; x < src.cols; x++) {
r = src.at<Vec3b>(y, x)[0];
g = src.at<Vec3b>(y, x)[1];
b = src.at<Vec3b>(y, x)[2];
val1 = saturate_cast<uchar>(b*(1+opacity));
if(val1 > 255) {
val1 = 255;
}
dst.at<Vec3b>(y, x)[0] =
saturate_cast<uchar>(r);
dst.at<Vec3b>(y, x)[1] =
saturate_cast<uchar>(g);
dst.at<Vec3b>(y, x)[2] =
saturate_cast<uchar>(val1);
}
}
}

In the above function what we are doing is taking the source image and converting it to a matrix of known number of rows and columns. Now, we loop over this matrix created and at each

position in the matrix calculate the red, green and blue values present there. There is a parameterized value “val” that determines the amount to which the color chosen is enhanced.

A simple variable val1 contains the enhanced value of the color chosen, here which is color blue. We modify and boost the color by the equation  :

B = B*(1 + (0.01f* val) )

Finally at this particular position in the matrix all the three values of the color are updated i.e. the original red and green color but the modified blue color.

The output of this filter converts images as below shown :

Before                                                                                   After

  

In the above method defined we instead of enhancing one color we can even modify two colors or all the three at the same time to get different effects as per the required needs. An example where I implemented a filter to enhance two colors at the same time is given below, the purpose of this filter is to add a violet color tone in the image.

The code for the filter is : 

void applyRedBlueEffect(cv::Mat &src, cv::Mat &dst, int val) {
register int x, y;
float opacity = val * 0.01f;
cvtColor(src, src, CV_BGRA2BGR);
dst = Mat::zeros(src.size(), src.type());
uchar r, g, b;
uchar val1,val3;

for (y = 0; y < src.rows; y++) {
for (x = 0; x < src.cols; x++) {
r = src.at<Vec3b>(y, x)[0];
g = src.at<Vec3b>(y, x)[1];
b = src.at<Vec3b>(y, x)[2];
val1 = saturate_cast<uchar>(r*(1+opacity));
if(val1 > 255) {
val1 = 255;
}

val3 = saturate_cast<uchar>(b*(1+opacity));
if(val3 > 255) {
val3 = 255;
}
dst.at<Vec3b>(y, x)[0] =
saturate_cast<uchar>(val1);
dst.at<Vec3b>(y, x)[1] =
saturate_cast<uchar>(g);
dst.at<Vec3b>(y, x)[2] =
saturate_cast<uchar>(val3);
}
}
}

 

Here we can easily see that there are two values that are updated at the same time i.e. the red and the blue part. The resultant image in that case will have two color values updated and enhanced.

Similarly, instead of two we can also update all the three colors to get uniform enhancement across each color and the resultant image to have all the three colors with a boost effect overall.

The output that we get after the filter that boosts the red and blue colors of an image is  :

 BEFORE                                                                 

AFTER

Resources

Continue ReadingImplementing Filters in Phimp.me Android App
Read more about the article Option to secure particular albums in Phimpme Android Application

Option to secure particular albums in Phimpme Android Application

In the Phimpme Android application, users can perform various operations on the albums available such as creating a zip file of the album, rename an album and many more. However, one another useful functionality that has been added to the Phimpme Android application is the option to secure particular albums. So in this post, I will be discussing the implementation of this security feature.

Step 1

Firstly, a view item for providing the option to enable security for particular albums is required to be added to the security settings layout. The two-state toggle switch widget provided by the Android framework along with a textview has been added as the required view item. A screenshot depicting the layout change is provided below.

The code snippet representing the operation is provided below.

<TextView
   android:id=“@+id/security_body_apply_folders_title”
   android:layout_width=“wrap_content”
   android:layout_height=“wrap_content”
   android:text=“@string/local_folder”
   android:textColor=“@color/md_dark_background”
   android:textSize=“@dimen/medium_text” />

<android.support.v7.widget.SwitchCompat
   android:id=“@+id/security_body_apply_folder_switch”
   android:layout_width=“wrap_content”
   android:layout_height=“wrap_content”
   android:layout_alignParentEnd=“true”
   android:layout_centerVertical=“true”
   android:layout_gravity=“center_vertical”
   android:button=“@null”
   android:hapticFeedbackEnabled=“true” />

Step 2

Now we need to keep track of the albums selected by the user to secure. This can be done by storing the selected album/albums paths in an ArrayList<String> which can be referred later when required in the process.

The required code snippet to perform the above mentioned operation is provided below.

holder.foldercheckbox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
if(b){
securedfol.add(a.getPath());
a.setsecured(true);
}else{
securedfol.remove(a.getPath());
a.setsecured(false);
}
}
});

Step 3

Now we need to store the selected albums preference in the SharedPreference so that the user’s security preference persists even when the user exits the application and the user doesn’t have to redo the securing operation the next time user launches the application. The ArrayList<String> object containing the path of the user choice albums are converted to JSON representation by the use of the Gson Java library and the string key denoting the JSON representation of the list is saved in the SharedPreference thereafter.

if(securedfol.size()>0){
   SharedPreferences.Editor editor = SP.getEditor();
   Gson gson = new Gson();
   String securedfolders = gson.toJson(securedfol);
   editor.putString(getString(R.string.preference_use_password_secured_local_folders), securedfolders);
   editor.commit();}

Now at the time of performing other operations on the secured folders, the list containing the secured folder paths is retrieved from SharedPreference and the choosen folder’s path is searched in the obtained list, then the user is asked to authenticate accordingly.

This is how we have implemented the functionality to secure particular albums in the Phimpme Android application. To get the full source code, please refer to the Phimpme Android Github repository listed in the resource section below.

Resources

1.Android Developer Guide –
https://developer.android.com/training/data-storage/shared-preferences

2.Github-Phimpme Android Repository – https://github.com/fossasia/phimpme-android/

3.Gson Java library tutorial –
http://www.vogella.com/tutorials/JavaLibrary-Gson/article.html

Continue ReadingOption to secure particular albums in Phimpme Android Application
Read more about the article Implementing Search Functionality in Phimpme Android Application.

Implementing Search Functionality in Phimpme Android Application.

In the Phimpme Android application, users are provided with options to perform various operations on the albums available such as move, creating a zip file of the album, rename an album and many more. However, one another useful functionality that has been added to the Phimpme Android application is the option to search albums. So in this post, I will be discussing the implementation of search functionality.

Step 1

Android framework provides developers with a search widget called SearchView that provides a user interface for the user to search a query and submit the request. So first setting up the widget in the action bar of the activity is required. The searchview widget can be added to the action bar as a menu item by adding the following lines in the XML menu resource file menu_albums.xml.

<item
   android:id=“@+id/search_action”
   android:title=“@string/search_menu”
   android:visible=“true”
   android:icon=“@drawable/ic_search_black_24dp”
   android:tint=“@color/white”
   app:actionViewClass=“android.support.v7.widget.SearchView”
   app:showAsAction=“always” />

Step 2

Now SearchView.OnQueryTextListener interface is used for initiating the search operation and listening to the callbacks for changes to the query text. For the purpose of listening to the querytext, two methods are used here both of which are listed below.

onQueryTextChanged(String Text) – This method is called every time the query text is changed by the user and returns a boolean value, false if SearchView should perform the default action of showing any suggestions and true if the action was handled by the listener.

onQueryTextSubmit(String query) – This method is called when the user submits a query which could be done with a key press on the keyboard or by pressing the submit button. It also returns a boolean value which is true if the query has been handled by the listener, otherwise false.

The code snippet for the implementation of the above mentioned interface is provided below.

searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
   @Override
   public boolean onQueryTextSubmit(String query) {
       return false;
   }

   @Override
   public boolean onQueryTextChange(String newText) {
       return searchTitle(newText);
   }
});

Step 3

In the final step, with the use of the onQueryTextChange method of the SearchView.onQueryTextListener interface the search operation and displaying the search results in the UI can be achieved. The onQueryTextChange method is called every time the search-query text changes. From the onQueryTextChange method, another method named searchTitle is invoked. Inside the searchTitle method the album names matching the search-query are searched from an Arraylist<Albums> containing all the albums displayed in the application. The albums obtained as a result of the search operation are then stored in another Arraylist<Album> which is thereafter passed as a parameter to the swapDataSet method of the AlbumsAdapter class to display the searched albums in the album view. The code snippet used for the above operations is provided below.

public boolean searchTitle(String newText) {
   if (!fromOnClick) {
       String queryText = newText;
       queryText = queryText.toLowerCase();
       final ArrayList<Album> newList = new ArrayList<>();
       for (Album album : albList) {
           String name = album.getName().toLowerCase();
           if (name.contains(queryText)) {
               newList.add(album);
           }
       }
       if(newList.isEmpty()){
           checkNoSearchResults(newText);
       }
       else{
           if(textView.getVisibility() == View.VISIBLE){
               textView.setVisibility(View.INVISIBLE);
           }
       }
       albumsAdapter.swapDataSet(newList);
   } else {
       fromOnClick = false;
   }
   return true;
}

This is how we have implemented the search functionality in the Phimpme Android application. To get the full source code, please refer to the Phimpme Android Github repository.

The screenshot for displaying the search result in album view is provided below.

Resources

1.Android Developer Guide – https://developer.android.com/reference/android/widget/SearchView

2.Github-Phimpme Android Repository – https://github.com/fossasia/phimpme-android/

3.Creating a search interface in Android – https://medium.com/@yugandhardcs21/creating-a-search-interface-in-android-dc1fd6a53b4

Continue ReadingImplementing Search Functionality in Phimpme Android Application.
Read more about the article Publish an Open Source app on Fdroid

Publish an Open Source app on Fdroid

Fdroid is a famous software repository hosted with numerous free and open source Android apps. They have a main repository where they allow developers hosting free and ad free software after a thorough check up on the app. This blog will tell you how to get your project hosted in their repository using steps I followed to publish the PSLab Android app.

Before you get started, make sure you have the consent from your developer community to publish their app on Fdroid. Fdroid requires your app to use all kind of open resources to implement features. If there is any closed source libraries in your app and you still want to publish it on Fdroid, you may have to reimplement that feature by any other mean without using closed source resources. They will also not allow to have Google’s proprietary “play-services” in your app along with proprietary ad services. You can find the complete inclusion policy document from their official page.

When your app is fully ready, you can get started with the inclusion procedure. Unlike how we are publishing apps on Google Play, publishing an app on Fdroid is as simple as sending a pull request to their main repository. That’s exactly what we have to do. In simple terms all we have to do is:

  1. Fork the Fdroid main data repository
  2. Make changes to their files to include our app
  3. Do a pull request

First of all you need a GitLab account as the Fdroid repository is hosted in GitLab. Once you are ready with a GitLab account, fork and clone the f-droid-data repository. The next step is to install the fdroid-server. This can be simply done using apt:

$ sudo apt install fdroidserver

Once that is done, go into the directory where you cloned the repository and run the following command to read current meta data where it saves all the information related to existing apps on Fdroid;

$ fdroid readmeta

This will list out various details about the current meta files. Next step is to add our app details into this meta file. This can be done easily using following command or you can manually create folders and files. But the following is safer;

$ fdroid import --url https://github.com/fossasia/pslab-android --subdir app

Replace the link to repository from the –url tag in the above command. For instance the following will be the link for fossasia-phimpme android;

$ fdroid import --url https://github.com/fossasia/phimpme-android --subdir app

This will create a file named as “org.fossasia.pslab” in the metadata directory. Open up this text file and we have to fill in our details.

  1. Categories
  2. License
  3. Web Site
  4. Summary
  5. Description

Description needs to be terminated with a newline and a dot to avoid build failures.

Once the file is filled up, run the following command to make sure that the metadata file is complete.

$ fdroid readmeta

Then run the following command to clean up the file

$ fdroid rewritemeta org.fossasia.pslab

We can automatically add version details using the following command:

$ fdroid checkupdates org.fossasia.pslab

Now run the lint test to see if the app is building correctly.

$ fdroid lint org.fossasia.pslab

If there are any errors thrown, fix them to get to the next step where we actually build the app:

$ fdroid build -v -l org.fossasia.pslab

Now you are ready to make the pull request which will then get reviewed by developers in Fdroid community to get it merged into their main branch. Make a commit and then push to your fork. From there it is pretty straightforward to make a pull request to the main repository. Once that is done, they will test the app for any insecurities. If all of them are passed, the app will be available in Fdroid!

Reference:

  1. Quick Start: https://gitlab.com/fdroid/fdroiddata/blob/master/README.md#quickstart
  2. Making merge requests: https://gitlab.com/fdroid/fdroiddata/blob/master/CONTRIBUTING.md#merge-requests
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Read more about the article Implementing Clickable Images

Implementing Clickable Images

PSLab Android application is a feature rich compact app to user interface the PSLab hardware device. Similarly the PSLab device itself is a compact device with a plenty of features to replace almost all the analytical instruments in a school science lab. When a first time user takes the device and connect it with the Android app, there are so many pins labeled with abbreviations. This creates lots of complications unless the user checks the pinout diagram separately.

As a workaround a UI is proposed to integrate a layout containing the PSLab PCB image where user can click on each pin to get a dialog box explaining him what that specific pin is and what it does. This implementation can be done it two ways;

  • Using an Image map
  • Using (x,y) coordinates

The first implementation is more practical and can be applied with any device with any dimension. The latter requires some transformation to capture the correct position when user has clicked on a pin. So the first method will be implemented.

The idea behind using an image map is to have two images with exact dimensions on top of each other. The topmost image will be the color map which we create ourselves using unique colors at unique heat points. This image will have the visibility setting invisible as the main idea is to let the  user see a meaningful image and capture the positions using a secondary in the back end.

To make things much clear, let’s have a look at a color map image I am suggesting here for a general case.

If we overlap the color map with the PSLab layout, we will be able to detect where user has clicked using Android onTouchEvent.

@Override
public boolean onTouchEvent(MotionEvent ev) {
   final int action = ev.getAction();
   final int evX = (int) ev.getX();
   final int evY = (int) ev.getY();
   switch (action) {
       case MotionEvent.ACTION_UP :
         int touchColor = getHotspotColor (R.id.backgroundMap, evX, evY);
         /* Display the relevant pin description dialog box here */
         break;
   }
   return true;
}

 
Color of the clicked position can be captured using the following code;

public int getHotspotColor (int hotspotId, int x, int y) {
   ImageView img = (ImageView) findViewById (hotspotId);
   img.setDrawingCacheEnabled(true);
   Bitmap hotspots = Bitmap.createBitmap(img.getDrawingCache());
   img.setDrawingCacheEnabled(false);
   return hotspots.getPixel(x, y);
}

 
If we go into details, from the onTouchEvent we capture the (x,y) coordinates related to user click. Then this location is looked up for a unique color by creating a temporary bitmap and then getting the pixel value at the captured coordinate.

There is an error in this method as the height parameter always have an offset. This offset is introduced by the status bar and the action bar of the application. If we use this method directly, there will be an exception thrown out saying image height is less than the height defined by y.

Solving this issue involves calculating status bar and actionbar heights separately and then subtract them from the y coordinate.

Actionbar and status bar heights can be calculated as follows;

Rect rectangle = new Rect();
Window window = getWindow();
window.getDecorView().getWindowVisibleDisplayFrame(rectangle);
int statusBarHeight = rectangle.top;
int contentViewTop = window.findViewById(Window.ID_ANDROID_CONTENT).getTop();
int titleBarHeight= contentViewTop - statusBarHeight;

 
Using them, we can modify the captured coordinates as follows;

int touchColor = getHotspotColor (R.id.imageArea, evX, evY - statusBarHeight);

 
This way the exception is handled by adjusting the cursor position. Once this is done, it is all about displaying the correct pin description dialog box.

Reference:

Calculate status bar height: https://stackoverflow.com/questions/3407256/height-of-status-bar-in-android

Continue ReadingImplementing Clickable Images
Read more about the article Option to exclude albums in Phimpme Android Application

Option to exclude albums in Phimpme Android Application

In the Phimpme Android Application, users can perform various operations on the albums available such as move, creating a .zip file of the album, rename an album, delete the album and much more. However one another important functionality that has been implemented in the application is the option to exclude album/albums. In this post we will be discussing how we achieved the functionality to exclude albums in Phimpme Android Application.

Step 1

First we need to keep track of the albums selected by the user to exclude. This can be done by storing the selected albums in an Arraylist<Album> which can be referred later when required for the process of exclusion. The storing of the albums can be done with the help of following lines of code.

private int toggleSelectAlbum(int index) {
 if (dispAlbums.get(index) != null) {
   dispAlbums.get(index).setSelected(!dispAlbums.get(index).isSelected());
   if (dispAlbums.get(index).isSelected()) selectedAlbums.add(dispAlbums.get(index));
   else selectedAlbums.remove(dispAlbums.get(index));
 }
 return index;
}

Step 2

After the selected albums are stored in an Arraylist<Album>, a function call of excludeSelectedAlbums() of HandlingAlbums class is done passing in Context as the parameter. In the method excludeSelectedAlbums() the selected albums are retrieved from the Arraylist one by one and another method excludeAlbum() is called with the album, context being passed as the parameters. The code snippet performing the above operation is provided below.

public void excludeSelectedAlbums(Context context) {
 for (Album selectedAlbum : selectedAlbums)
   excludeAlbum(context, selectedAlbum);
 clearSelectedAlbums();
}

Step 3

Thereafter an instance of class CustomsAlbumHelper is created and excludeAlbum() method is called with path of the album passed as parameter, and the selected album is removed from the list containing the currently displayed albums. Code snippets for the above operations are provided below.

private void excludeAlbum(Context context, Album a) {
 CustomAlbumsHelper h = CustomAlbumsHelper.getInstance(context);
 h.excludeAlbum(a.getPath());
 dispAlbums.remove(a);
}

Step 4

Now in the excludeAlbum() method of CustomsAlbumHelper class a writable instance of albums_settings sqlite database is obtained. A check is performed if the current album is present in the albums table or not, if not then a row representing the current album is created. Thereafter the excluded value for the current album in the table is updated to integer 1 denoting that the album is excluded. The code snippet required for the above mentioned operations are provided below.

public void excludeAlbum(String path) {
   SQLiteDatabase db = this.getWritableDatabase();
   checkAndCreateAlbum(db, path);
   ContentValues values = new ContentValues();
   values.put(ALBUM_EXCLUDED, 1);
   db.update(TABLE_ALBUMS, values, ALBUM_PATH+“=?”, new String[]{    path});
   db.close();
}

This is how we have achieved the functionality of excluding albums in the Phimpme Android application. To get the full source code, please refer to the Phimpme Android GitHub repository listed in the resources section below.

The screenshot for the display of the excluded albums is provided below.

Resources

  1. Android Developer Guide –https://developer.android.com/training/data-storage/sqlite.html
  1. Github-Phimpme Android Repository –https://github.com/fossasia/phimpme-android/
  1. Sqlite Operations Tutorial – https://www.androidhive.info/2011/11/android-sqlite-database-tutorial/
Continue ReadingOption to exclude albums in Phimpme Android Application
Read more about the article Option to hide albums in Phimpme Android Application

Option to hide albums in Phimpme Android Application

In Phimpme Android Application, users can perform various operations on the albums available such as move, creating a .zip file for the album, delete the album, exclude an album, rename an album, pin an album to the top and more. However one another important functionality that has been added in the application is the option to hide  album/albums. So in this post I will be discussing how we achieved the functionality to hide albums in Phimpme Android Application.

Step 1

First we need to get the albums which are selected to be hidden. This can be done by storing the selected items in an Arraylist<Album> which will keep track of the users choice to hide albums. This can be achieved with the following lines of code.

private int toggleSelectAlbum(int index) {
 if (dispAlbums.get(index) != null) {
   dispAlbums.get(index).setSelected(!dispAlbums.get(index).isSelected());
   if (dispAlbums.get(index).isSelected()) selectedAlbums.add(dispAlbums.get(index));
   else selectedAlbums.remove(dispAlbums.get(index));
 }
 return index;
}

Step 2

After storing of the albums to be hidden a function hideSelectedAlbums() is called with Context being passed as the parameter. Now inside this function we retrieve the albums looping through the Arraylist that stores the albums to be hidden and call another function hideAlbum() passing in the album and context as the parameters. The code snippet representing the above operation is given below.

public void hideSelectedAlbums(Context context) {
 for (Album selectedAlbum : selectedAlbums)
   hideAlbum(selectedAlbum, context);
 clearSelectedAlbums();
}

Step 3.

Now a .nomedia file is added to the directories/albums which are to be hidden and the android Media Scanner System service is triggered thereafter. As a result of the presence of the .nomedia file inside the directory the Media Scanner service won’t scan the particular directory/album thereby the album will not be picked up at the time of displaying the albums. The code snippet to perform the mentioned operation is provided below.

File dirName = new File(path);
File file = new File(dirName, “.nomedia”);
if (!file.exists()) {
 try {
   FileOutputStream out = new FileOutputStream(file);
   out.flush();
   out.close();
   scanFile(context, new String[]{ file.getAbsolutePath() });
 } catch (Exception e) {
   e.printStackTrace();
 }
}

The screenshot for the display of hidden folders is provided below.

This is how we have achieved the functionality of hiding albums in the Phimpme Android application. To get the full source code, please refer to the Phimpme Android GitHub repository listed in the resources section below.

Resources

  1. Android Developer Guide – https://developer.android.com/reference/android/media/MediaScannerConnection.html
  2. Github-Phimpme Android Repository –https://github.com/fossasia/phimpme-android/
  3. Hiding directories using .nomedia file – http://www.easycodeway.com/2016/08/hide-files-in-android-using-nomedia-file.html
Continue ReadingOption to hide albums in Phimpme Android Application