Develop Reference

How to change the action bar color and open a file on click?

I'm working now on an app for Android and there are two things that I don't know how to do.
I want to change the colour of the action bar at the request of the user, so I want to change it dynamically. I see some answers that say that I need to use:
ActionBar bar = getActionBar();
bar.setBackgroundDrawable(new ColorDrawable(Color.parseColor("#004D40")));
But for some reason, it does not work for me.
I've added to my app option to download a file, but I do it in an unusual way so it does not create a notification when the download is complete. I want to give my user an easy way to get to the file. Can I create a button that opens the file when clicked?
Thanks!

1) For that I would recommend you having Example here Toolbar View and set it as your Actionbar. Just add this view at the top:
<android.support.v7.widget.Toolbar
android:id="#+id/my_toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
android:elevation="4dp"
android:theme="#style/ThemeOverlay.AppCompat.ActionBar"
app:popupTheme="#style/ThemeOverlay.AppCompat.Light"/>
And then in Activity
Toolbar myToolbar = (Toolbar) findViewById(R.id.my_toolbar);
setSupportActionBar(myToolbar);
After this you can change everything you want to the view myToolbar. Set background color etc. It will work. Using just Actionbar is old and depricated approach.
2) Yes you can, it is like opening new Activity with intent. Android has some inbuilt Intent Action Type which helps you to Open or View specific files, but for this you need to know which type of file you are going to handle.
Suppose If you have file type which categorized in document type you can use,
ACTION_OPEN_DOCUMENT with specific MIME_TYPE (Android 4.4 or Higher)
or If you going to handle some media file (Audio/Video)
you can use,
ACTION_VIEW
To identify MIME_TYPE of specific file you can use function
guessContentTypeFromName (String url)Link
Or getMimeTypeFromExtension(String extension)Link
Hope this helps :)

You can't change the color because you should call getSupportActionBar() and it's also for api >11;
getSupportActionBar().setBackgroundDrawable(new ColorDrawable(getResources().getColor(android.R.color.black)‌​));
or
getSupportActionBar().setBackgroundDrawable(new ColorDrawable(Color.parseColor("#004D40")​));
About your second question, we need more info and your code where you download file. You totally can access files onClick but you need to know the file type and the directory where you store the files and target api to check runtime permissions for example
I suggest you ask another question with all your code and this info

Display pdf image on click that is scrollable in another page

What I want to happen is that when a button is clicked, the user gets sent to another page and then a pdf file is openly displayed (the contents of it) and it is scrollable.
I have absolutely no clue how to go about this, which is why I am posting it in another question because I am aware that there is probably an answer that already explains how to do this, but I am so new to it I do not have any clue how to start!
The software is for an app (android studio), so I cannot use javascript to do it ( I do not think)
It is not a duplicate of that because I really have no clue how to solve the problem as I am too 'beginner-like' and also the fact that that article shows how to do it with internet and I cannot do it with internet for my application

I have done similar case in past. What I did is, I load a image by image from the pdf to android ImageView by passing the page number. I did this using Debenu PDF Library For Android
When User click your first Button Open separate activity and get the first page as a Image by passing page number to the pdf library inside the OnCreate method of Activity
If you need more help, feel free to ask..

There are already detailed answers on Stackoverflow: For instance:
How to open/display documents(.pdf, .doc) without external app?
In order to go to a new Page you use :
startActvity(new Intent(context, ActivityName.class));
The new Activity holds an WebView
<WebView
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/webView1"
android:layout_width="match_parent"
android:layout_height="match_parent" />
Then you can use
WebView wv = (WebView)findViewById(R.id.webView);
wv.getSettings().setJavaScriptEnabled(true);
wv.getSettings().setPluginsEnabled(true);
wv.getSettings().setAllowFileAccess(true);
wv.loadUrl(doc);

Check this, Hope it will help -
1) Render a PDF file using Java on Android
2) https://github.com/jblough/Android-Pdf-Viewer-Library

android change imageview programmatically

I am making an android app where the same imageview is displayed every time the user enters a value. but I want the imageview to be changed every time the user enters a value. I wrote a code to do this but the problem is after the first image is displayed I face black screen and it takes me to the first page in the app, it doesn't crash just shows black screen.
here is the imageview code in xml file:
<ImageView
android:id="#+id/ImageSuccess"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:layout_gravity="center"
android:layout_marginBottom="20dip"
android:layout_marginTop="20dip"
android:scaleType="centerInside"
android:src="#drawable/image1" />
and here where I changed the imageview in java file:
ImageView myImage= (ImageView) findViewById(R.id.ImageSuccess);
if(userVlue.equals("SCHOOL")){
myImage.setImageResource(R.drawable.image1);
}
else if(userVlue.equals("CAR")){
myImage.setImageResource(R.drawable.image2);
}
else if(userVlue.equals("TOY")){
myImage.setImageResource(R.drawable.image3);
}

One of myImage or userVlue is not set properly and probably is null.
Debug and share logs. Your partcular activity is getting distroyed probably because of nullpointexception hence returning to main activity in backtrack.
I tried with a sample app and your logic is working perfectly.
You are handling user action on some UI element, when you do findViewById, cotext is that UI element, so this method searches ImageSuccess in children of it. Try giving page layout as rootlayout and do rootlayout.findViewById("ImageSuccess");

I found the solution finally, the black screen appeared because the images were only in the drawable file, so I needed to add the images in all drawbridge folders such as drawable-ldp, drawable-ldpi etc...., so that the app can work in different phone sizes.

Android tab bar with different fragments and different action bar icons

Problem Description and Question
I'm using tab activity with action bar. In the HOME tab I have GridView which contains some items, like it is shown in the image below (Hot Lines, Taxi, Restaurants etc)
Wen user click on the items in the grid view I want my application to take following actions:
Change icon of application to grid view item image on which I pressed.
Change the test near the icon
Add standard back button near icon, which will go back to grid view screen.
Change the tab fragment to the one which I specify.
Like it is shown in the image below:
As I never deal with this kind of problems can you please give me example or share some link with me of how I can do this? and can I do this at all?

This might help:
Android studio - is possible to add tabs pointing to fragments from designer?
It is not exactly what you want, but a good start. If you are willing to put a bit of work in it, you should be able to get what you want. If you have a basic Frame to work with and more specific problems with this matter I will gladly help you out ^^
John

The first link you can check is THIS.
And you should read more about ActionBar.
The last thing is it's better if you google it first and try to write a code and when you got stuck somewhere share your code with us and ask for help.

You have to use actionbarsherlock library for it.
use android.support.v4.app.FragmentTabHost and TabWidget in the xml as shown below :
<android.support.v4.app.FragmentTabHost
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:ads="http://schemas.android.com/apk/lib/com.google.ads"
style="#style/yourstyle"/>
<FrameLayout
android:id="#+id/realtabcontent"
style="#style/realtabFrameContentStyle" />
<TabWidget
android:id="#android:id/tabs"
style="#style/yourtabstyle" />
</android.support.v4.app.FragmentTabHost>
Use SherlockFragmentActivity for showing the tabs.
In the activities code use following code (preferably in a function) to set the ctionbar icon and text :
activity.getSupportActionBar().setDisplayShowCustomEnabled(true);
activity.getSupportActionBar().setCustomView(R.layout.your_action_barlayout);
((TextView) (activity.getSupportActionBar().getCustomView().findViewById(R.id.action_bar_title))).setText("your title");
ImageView homeButton = ((ImageView) (activity.getSupportActionBar().getCustomView().findViewById(R.id.your_icon)));
homeButton.setVisibility(View.VISIBLE);
homeButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(context, YourHOmeActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
intent.addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP);
activity.startActivity(intent);
activity.finish();
}
});
ActionBar mActionBar = activity.getSupportActionBar();
mActionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
mActionBar.show();
then call this function with your icon and your text in your fragments onResume() method.

paste option for edittext

I have an edittext and I would like to paste some text in it. I can copy the text from some web page but I am not able to paste the text in my edittext control.How can I enable my edittext to paste some text.Here is my main.xml for edittext ;
enter code here
<EditText
android:id="#+id/enter"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight= "2"
android:scrollbars="vertical"
android:textColor="#color/black"
/>
Thanks

This is on Android 4.4.2 Samsung S4;
Documentation for TextView says that:
To allow users to copy some or all of the TextView's value and paste
it somewhere else, set the XML attribute android:textIsSelectable to
"true" or call setTextIsSelectable(true). The textIsSelectable flag
allows users to make selection gestures in the TextView, which in turn
triggers the system's built-in copy/paste controls.
There is also another Textview attribure called android:cursorVisible which determines if the system should be invoked about the copy/paste callbacks.
By default I believe both of these are true and selection/copy/paste mechanics are already enabled. I could not change that behaviour by using android:textIsSelectable="false" but if I set android:cursorVisible="false" initially you can't paste anything inside the EditText. Only after you type something in, cursor and selection behaviour becomes enabled again. Maybe this should be handled inside the code rather than in the layout xmls, or it might be related to android:inputType which also did not make a difference for me.
So try setting android:cursorVisible="true" in your EditText's layout xml if paste is not enabled by default.

According to your problem if you copied some data any where in your system and you want to paste it in some specific variable, like Edit TextBox, Textview etc, then this code will surely help you.
ClipboardManager clipMan = (ClipboardManager)getSystemService(v.getContext().CLIPBOARD_SERVICE);
myEdtTxt.setText(clipMan.getText());
Note:- here the clipMan object will store the data whenever copied process take place and we will return that data from that object and will set it,

To enable the standard copy/paste for TextView, U can choose one of the following:
Change in layout file:
Either add below property to your TextView
android:textIsSelectable="true"
and In your Java class write this line to set it programmatically.
myTextView.setTextIsSelectable(true);
if fragment try with
mContext.myTextView.setTextIsSelectable(true);
And long press on the TextView you can see copy/paste action bar.

Try setting the inputType="text" for the EditText field