I am making an app called ROME, about the city of Rome. I have a activity called eten which means food and I want the activity to open a certain pdf-file called etenlijst.pdf when openened.
I got to the following code:
public class Eten extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_eten);
// Show the Up button in the action bar.
// getActionBar().setDisplayHomeAsUpEnabled(true);
/**** This looks like a good place for it *****/
Button OpenPDF = (Button) findViewById(R.id.OpenPdfButton);
OpenPDF.setOnClickListener(new View.OnClickListener()
{
public void onClick(View v)
{
File pdfFile = new File("/ROME/Etenlijst.pdf");
if(pdfFile.exists())
{
Uri path = Uri.fromFile(pdfFile);
Intent pdfIntent = new Intent(Intent.ACTION_VIEW);
pdfIntent.setDataAndType(path, "application/pdf");
pdfIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
try
{
startActivity(pdfIntent);
}
catch(ActivityNotFoundException e)
{
Toast.makeText(Eten.this, "Installeer een geschikte applicatie om PDF's mee te openen", Toast.LENGTH_LONG).show();
}
}
}
});
}
}
But whenever I go to this activity in my app or click the button it won't open the file or give the toast?
Do you now why?
Thanks in advance,
Ide
Related
I want to let users choose background colors with animation in BackgroundActivity and saving that changed background color into MainActivity.
When a user clicks backgroundChange button on MainActivity, it moves to BackgroundActivity. Then there are a few different colors to choose. After a user click Save button after choosing color on BackgroundActivity, it is going back to MainAcitivity. My problem is I don't know how to save that changed background color from BackgroundAcivity to MainAcivity.
As a beginner, I cannot understand well how to use SharedPreferences.
I checked several videos and searching many questions for hours about it, but still, I cannot figure out how to use SharedPreferences correctly on my own code.
BackgroundAcivity is really long that I will only put the first part. Could you tell me how to save this background change?
MainActivity
public class MainActivity extends AppCompatActivity {
Button backgroundChange;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
backgroundChange = findViewById(R.id.backgroundChange);
backgroundChange.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(MainActivity.this, BackgroundActivity.class);
startActivity(intent);
}
});
}
}
BackgroundActivity
public class BackgroundActivity extends AppCompatActivity {
Button btn_blue, btn_purple, btn_orange, btn_save;
View holderBg, dynamicBg;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_background);
btn_save = findViewById(R.id.btn_save);
btn_save.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(BackgroundActivity.this, MainActivity.class);
startActivity(intent);
}
});
btn_blue = findViewById(R.id.btn_blue);
btn_purple = findViewById(R.id.btn_purple);
btn_orange = findViewById(R.id.btn_orange);
holderBg = findViewById(R.id.holderBg);
dynamicBg = findViewById(R.id.dynamicBg);
//set the first-time background
holderBg.setBackgroundResource(R.drawable.bg_blue);
holderBg.setScaleY(3);
holderBg.setScaleX(3);
//set the scale of button clicked
btn_blue.setScaleY(1.5f);
btn_blue.setScaleX(1.5f);
btn_blue.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//scale animation
btn_blue.animate().translationY(20).scaleX(1.5f).scaleY(1.5f).setDuration(800).start();
//default the scale buttons
btn_purple.animate().translationY(0).scaleX(1).scaleY(1).setDuration(350).start();
btn_orange.animate().translationY(0).scaleX(1).scaleY(1).setDuration(350).start();
//change the background
dynamicBg.animate().scaleX(3).scaleY(3).setDuration(800).start();
dynamicBg.setBackgroundResource(R.drawable.bg_blue);
//change color of button
btn_save.setTextColor(Color.parseColor("#3498db"));
//timer for change the holderbg
final Handler handler = new Handler();
handler.postDelayed(new Runnable() {
#Override
public void run() {
holderBg.setScaleX(3);
holderBg.setScaleY(3);
holderBg.setBackgroundResource(R.drawable.bg_blue);
dynamicBg.setScaleX(0);
dynamicBg.setScaleY(0);
}
}, 850);
}
});
}
}
You can use a bundle to transfer your data across Activity.
Saving data
Intent intent = new Intent(context, YourActivity.class);
intent.putExtra(KEY, "your value here");
startActivity(intent);
Then to retrieve data.
Intent intent = getIntent();
if (intent != null ) { //Null Checking
String strData= intent.getStringExtra(KEY);
// do your work with `strData`
}
I'm making an app where it uses intent to send data to another app. In case, the other app, which is supposed to receive data from my app, is not installed on users's device then it redirects user to play store with toast message asking user to install it. I used "if else" to achieve this. It worked all good until I found that if the other app is disabled by user (OEM installed app which can't be uninstalled), then my app crashes. In such a condition, I want to let user know that the app is disabled by them and ask them to enable it (through toast message). How can I achieve this?
Here is my complete code:
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Creates button view which is connected to a view in the XML layout, which gets triggered on touching the view.
TextView textView = (TextView) findViewById(R.id.location);
textView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// Use package name which we want to check
boolean isAppInstalled = appInstalledOrNot("com.google.android.apps.maps");
if(isAppInstalled){
Uri gmmIntentUri = Uri.parse("geo:00,0000,00,0000");
Intent mapIntent = new Intent(Intent.ACTION_VIEW, gmmIntentUri);
mapIntent.setPackage("com.google.android.apps.maps");
startActivity(mapIntent);
} else {
Uri uri2 = Uri.parse("market://details?id=com.google.android.apps.maps");
Intent goToMarket = new Intent(Intent.ACTION_VIEW, uri2);
Toast.makeText(MainActivity.this, "Google Maps not Installed", Toast.LENGTH_SHORT).show();
startActivity(goToMarket);
}
}
});
}
private boolean appInstalledOrNot(String uri) {
PackageManager pm = getPackageManager();
try {
pm.getPackageInfo(uri, PackageManager.GET_ACTIVITIES);
return true;
} catch (PackageManager.NameNotFoundException e) {
}
return false;
}
}
I'm not sure if this will work for you, but since you know the package name, you could try this to do a check beforehand.
I'm creating an app to open a PDF application from a button, but what I did is not going well.
In my layout there is only one button , which seeks want and open a PDF file.
Not giving error in Eclipse , just in tablet appears " readerPDF stopped ."
I do not know what to do. somebody help me.
Sorry for my english.
public class ReaderActivity extends Activity {
private Button btnOpen;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_reader);
btnOpen.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
String filename = null;
File file = new File(Environment.getExternalStorageDirectory().getAbsolutePath() +"/"+ filename);
Intent target = new Intent(Intent.ACTION_VIEW);
target.setDataAndType(Uri.fromFile(file),"application/pdf");
target.setFlags(Intent.FLAG_ACTIVITY_NO_HISTORY);
Intent intent = Intent.createChooser(target, "Open File");
try {
startActivity(intent);
} catch (ActivityNotFoundException e) {
}
}
});
}
}
filename is null, so the path you are passing to the third-party app does not point to a PDF file.
I have three images with me and i want them to appear on first layout xml like a splash view so that they can be viewed only once i.e that activity will be called only once when app get's installed or if app get's a new update otherwise app should always start from the Second activity, i don't know how should i begin with this :
Can any one tell me any idea how this can be done.
To show splash for only once.
Next part of this question is here
Coding will be much appreciated.
Save a flag in the Preferences when you start up the application, after you've done the welcome screen stuff. Check for this flag before you show the welcome screen. If the flag is present (in other words, if it's not the first time), don't show it.
In your activity:
SharedPreferences mPrefs;
final String welcomeScreenShownPref = "welcomeScreenShown";
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mPrefs = PreferenceManager.getDefaultSharedPreferences(this);
// second argument is the default to use if the preference can't be found
Boolean welcomeScreenShown = mPrefs.getBoolean(welcomeScreenShownPref, false);
if (!welcomeScreenShown) {
// here you can launch another activity if you like
// the code below will display a popup
String whatsNewTitle = getResources().getString(R.string.whatsNewTitle);
String whatsNewText = getResources().getString(R.string.whatsNewText);
new AlertDialog.Builder(this).setIcon(android.R.drawable.ic_dialog_alert).setTitle(whatsNewTitle).setMessage(whatsNewText).setPositiveButton(
R.string.ok, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
}).show();
SharedPreferences.Editor editor = mPrefs.edit();
editor.putBoolean(welcomeScreenShownPref, true);
editor.commit(); // Very important to save the preference
}
}
Try this :
public class MainActivity extends Activity {
private Thread mSplashThread;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
try {
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.splash);
final MainActivity sPlashScreen = this;
mSplashThread = new Thread() {
#Override
public void run() {
try {
synchronized (this) {
wait(4000);
}
} catch (InterruptedException ex) {
}
finish();
Intent intent = new Intent();
intent.setClass(sPlashScreen, StartNewActivity.class);// <-- Activity you want to start after Splash
startActivity(intent);
}
};
mSplashThread.start();
} catch (Exception e) {
}
}
#Override
public boolean onTouchEvent(MotionEvent evt) {
try {
if (evt.getAction() == MotionEvent.ACTION_DOWN) {
synchronized (mSplashThread) {
mSplashThread.notifyAll();
}
}
} catch (Exception e) {
}
return true;
}
}
you put an Image in splash.xml to show
to do this you have to detect the first launch of your application. To do so you can store a boolean value as #Nirav suggested.
And for the splash screen, You can consider using Fragments and ViewPager to create an activity which will only be shown for the first time
public class OpenPdf extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button button = (Button) findViewById(R.id.OpenPdfButton);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
File file = new File("/sdcard/example.pdf");
if (file.exists()) {
Uri path = Uri.fromFile(file);
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setDataAndType(path, "application/pdf");
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
try {
startActivity(intent);
}
catch (ActivityNotFoundException e) {
Toast.makeText(OpenPdf.this,
"No Application Available to View PDF",
Toast.LENGTH_SHORT).show();
}
}
}
});
}
}
I have tried this above code but no output can been seen on emulator.Please help me to solve my problem of reading a PDF on emulator
I think the issue is in the Activity where you're trying to show the .pdf.
I haven't tried opening any .pdf files in any of my apps, but a cursory search says there is no native, easy way to do it. In other words, there is no Android class that makes it a snap to show your .pdf files - so you'll have to use a third party library, or roll your own.
See Render a PDF file using Java on Android