Develop Reference

How to fit all elements in gridview in the whole display?

I am new in android and want to create a gridview with some elements (element with Text and Image) and was guided by this link https://www.viralandroid.com/2016/04/android-gridview-with-image-and-text.html.
I have a layout for the activity screen:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/home_screen"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<GridView
android:id="#+id/grid_view_image_text"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:columnWidth="110dp"
android:numColumns="3"/>
</LinearLayout>
the layout for the gridview with text and image:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/android_custom_gridview_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center_horizontal"
android:orientation="vertical">
<ImageView
android:id="#+id/android_gridview_image"
android:layout_width="50dp"
android:layout_height="50dp"
android:layout_marginTop="15dp" />
<TextView
android:id="#+id/android_gridview_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="5dp"
android:textSize="25sp" />
</LinearLayout>
This is my code:
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.widget.AdapterView;
import android.widget.GridView;
import android.widget.Toast;
public class HomeScreenActivity extends AppCompatActivity {
private GridView androidGridView;
private String[] gridViewString = {
"Anlagenübersicht", "Instandhaltungsaufträge", "Handlungsleitfaden",
"Wiki", "Historie", "Fehlerdatenbank",
"Wartungsprotokoll", "Ersatzteile", "Werkzeugkasten",
"Remotezugriff", "Personal", "Über uns"
} ;
private int[] gridViewImageId = {
R.drawable.icons8_roboter_48, R.drawable.icons8_bestellung_48, R.drawable.icons8_aufgabenliste_48,
R.drawable.icons8_doktorhut_48, R.drawable.icons8_vergangenheit_48, R.drawable.icons8_datenbank_40,
R.drawable.icons8_wartung_48, R.drawable.icons8_ersetzen_48, R.drawable.icons8_werkzeugkasten_48,
R.drawable.icons8_assistent_48, R.drawable.icons8_gruppe_vordergrund_ausgewaehlte_48, R.drawable.icons8_ueber_48,
};
#Override
protected void onCreate(Bundle savedInstanceState) {
setTheme(R.style.AppTheme);
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home_screen);
CustomGridViewActivity adapterViewAndroid = new CustomGridViewActivity(HomeScreenActivity.this, gridViewString, gridViewImageId);
androidGridView= (GridView) findViewById(R.id.grid_view_image_text);
androidGridView.setAdapter(adapterViewAndroid);
androidGridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int i, long id) {
Toast.makeText(HomeScreenActivity.this, "GridView Item: " + gridViewString[+i], Toast.LENGTH_LONG).show();
}
});
}
}
But my Output is:
But I want that all elements will fill the display in height and with, that there will be no space like you can see here:

Finally, I found a solution from this link:
android How to stretch rows in the gridview to fill screen?
I had to set some attributes for my activity class, and use this:
DisplayMetrics metrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(metrics);
int width = metrics.widthPixels;
int height = metrics.heightPixels;
to determine the height and width.
After that, I had to set the Minimum with and height for my View.
For more informations, I recommend you to check the link above. :)

RecyclerView "No Results" TextView findViewById always returns null

I have a RecyclerView with a TextView in it's place as well for when no results are found.
This TextView when calling root.findViewById always returns null, I have tried re-cleaning the project, building the project over again. Nothing has helped.
Here are my imports:
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.os.Handler;
import android.os.HandlerThread;
import android.os.Message;
import android.support.v4.app.Fragment;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.text.TextUtils;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ProgressBar;
import android.widget.TextView;
import com.mypackage.commoncode.R;
Here is the code for the onCreateView:
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View root = inflater.inflate(R.layout.fragment_mail, container, false);
//
mProgressBar = (ProgressBar) root.findViewById(R.id.spinner);
mProgressBar.setVisibility(View.VISIBLE);
final Context context = root.getContext();
mEmptyView = (TextView) root.findViewById(R.id.empty_view);
mEmptyView.setVisibility(View.INVISIBLE);
// set list
float ht = BitmapUtils.convertDpToPixel(8, context);
mLinearLayoutManager = new LinearLayoutManager(context);
mListView = (RecyclerView) root.findViewById(android.R.id.list);
mListView.setLayoutManager(mLinearLayoutManager);
mListView.setVisibility(View.INVISIBLE);
mListView.addItemDecoration(new VerticalSpaceItemDecoration(Float.valueOf(ht).intValue()));
mListAdapter = new InboxListAdapter(context);
mListAdapter.setOnInboxClickListener(this);
mListView.setAdapter(mListAdapter);
if (mBackground == null) {
mBackground = new HandlerThread("background", android.os.Process.THREAD_PRIORITY_BACKGROUND);
mBackground.start();
mBackgroundCallback = new BackgroundCallback(this.getActivity().getApplicationContext(), mCurrentKid);
mBackgroundHandler = new Handler(mBackground.getLooper(), mBackgroundCallback);
}
final Handler displayHandler = new Handler(new HandlerCallback(this));
mBackgroundCallback.setDisplayHandler(displayHandler);
//
retrieveInboxList(context);
return root;
}
Here is the XML for the layout:
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ProgressBar
android:id="#+id/spinner"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center|center_horizontal" />
<android.support.v7.widget.RecyclerView
android:id="#+id/android:list"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<TextView
android:id="#+id/empty_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:visibility="invisible"
android:text="#string/No_Results_found" />
</FrameLayout>
Any ideas as to why the empty_view TextView is always null?
Logcat error:
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setVisibility(int)' on a null object reference
at this line:
mEmptyView.setVisibility(View.INVISIBLE);

The view xml referenced does not have the view with the id your are trying to retrieve. Make sure the xml posted is the correct one or that you have another xml for this resolution that maybe is not containing the view.

Horizontal scrollview listing multiple image side by side

I am using horizontal scroll view to list images . But what is happening is multiple images are showing side by side. what I want is to show one image taking full screen width and on scroll show next image
my code is as follows
page4.xml:
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="match_parent">
<HorizontalScrollView
android:id="#+id/horizontal_scroll"
android:layout_width="fill_parent"
android:layout_height="match_parent"
android:fillViewport="true">
<LinearLayout
android:id="#+id/linear"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:scaleType="fitCenter">
</LinearLayout>
</HorizontalScrollView>
</RelativeLayout>
page4.java:
package com.example.namrathasrinivas.karnatakatemples;
import android.app.ListActivity;
import android.graphics.BitmapFactory;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.text.method.ScrollingMovementMethod;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.animation.Animation;
import android.view.animation.TranslateAnimation;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Gallery;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import android.content.Intent;
/**
* Created by namrathasrinivas on 23/07/15.
*/
public class page4 extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.page4);
int[] drawables = {R.drawable.img1,R.drawable.img2,R.drawable.img3,R.drawable.img4,R.drawable.img5,R.drawable.img6};
LinearLayout layout = (LinearLayout) findViewById(R.id.linear);
for (int i = 0; i < 6; i++) {
ImageView imageView = new ImageView(this);
imageView.setId(i);
imageView.setPadding(5, 5, 5, 5);
imageView.setImageBitmap(BitmapFactory.decodeResource(
getResources(), drawables[i]));
imageView.setScaleType(ImageView.ScaleType.FIT_CENTER);
layout.addView(imageView);
}
}
}

ViewPager is what you're looking for.

I suggest you used RecyclerView or Viewpager
Articles Collection for RecyclerView

add LinearLayout property
android:baselineAligned="true"

If you really want image to be placed in Horizontal scroll view instead of ViewPagers then set the minimum_width property to your ImageView like below
imageView.setMinimumWidth(getScreenWidth());
private int getScreenWidth() {
WindowManager wm = (WindowManager) getSystemService(Context.WINDOW_SERVICE);
Display display = wm.getDefaultDisplay();
Point size = new Point();
display.getSize(size);
return size.x;
}

Instead of horizontal scroll view you can use recyclerview as horizontal view is easy for use.
Implementation is like:
mRecyclerViewImages.setLayoutManager(new LinearLayoutManager(getContext(),LinearLayoutManager.HORIZONTAL,true));
Set below view to adapter (take singal image view like):
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="5dp"
android:background="#color/cpb_white"
app:cardElevation="5dp"
app:cardUseCompatPadding="true">
<ImageView
android:id="#+id/test_image"
android:layout_width="#dimen/profile_image_size"
android:layout_height="#dimen/profile_image_size"
android:layout_margin="2dp"
android:background="#DBDBDB"
android:scaleType="center"
android:src="#drawable/camera" />
</android.support.v7.widget.CardView>

Android Studio, adding multiple images on click

JAVA:
package com.example.scott.testapplication;
import android.app.Activity;
import android.media.Image;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;
public class HomeScreen extends Activity {
RelativeLayout Backround;
Button InitButton;
ImageView image;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home_screen);
Backround = (RelativeLayout) findViewById(R.id.Backround);
InitButton = (Button) findViewById(R.id.InitButton);
image = (ImageView) findViewById(R.id.image);
InitButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
/*insert code here*/
}
});
}
}
In order to insert the image, i'm thinking that I need to use a command like ImageView image = new (image), and then use another command to draw it on the display. I dont know which commands I should use.
XML:
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/Backround"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
android:paddingBottom="#dimen/activity_vertical_margin">
<ImageView
android:layout_width ="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/image"
android:scaleType="fitXY"
android:src="#drawable/DESERT2" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Initiate"
android:id="#+id/InitButton"
android:layout_centerVertical="true"
android:layout_centerHorizontal="true"
android:layout_gravity="center_vertical" />
</RelativeLayout>
I would like to create the image on the event of the click of a button, I also created the ImageView in the xml file. Not sure if I should change something there.

you can use
image.setImageResource(R.drawable.yourDesiredImageName);

How to Change a size of fragment?

Pretty new to android development, I need to know how I can change the size of my ListView in my fragment pragmatically to cover the entire screen? match_parent, fill_parent didn't work.
I have hard coded values of 500dp
Here is my fragment
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<ListView
android:id="#android:id/list"
android:layout_width="500dp"
android:layout_height="500dp"
android:divider="#null"
android:dividerHeight="0dp"
android:layout_marginTop="0dp">
</ListView>
</RelativeLayout>
and here is JAVA my fragment code:
import android.app.ListFragment;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.FrameLayout;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.view.ViewGroup.LayoutParams;
import android.widget.LinearLayout;
import java.util.List;
public class MyFragment extends ListFragment {
List<data> flowers = new datadata().getdatas();
public MyFragment() {
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
dataArrayAdapter adapter = new dataArrayAdapter(getActivity(),
R.layout.data_listitem,
flowers);
setListAdapter(adapter);
}
#Override
public View onCreateView(LayoutInflater inflater,
ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.my_fragment, container, false);
return rootView;
}
}
here is my main Activity class
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/myContainer"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:scrollbarStyle="insideOverlay"
android:scrollbars="none"
android:fadeScrollbars="true"
android:fitsSystemWindows="true"
android:layout_gravity="top"
>
</ScrollView >
and this is my main activity java code:
package mshirvan.example.com.netplex;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.Fragment;
import android.content.Intent;
import android.media.Image;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.FrameLayout;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.RelativeLayout;
import android.widget.Toast;
import android.view.View.OnClickListener;
import data.row1;
public class MainActivity extends Activity {
public static float screenx = 0;
public static float screeny = 0;
public static int screenpixelx = 0;
public static int screenpixely = 0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ScreenUtility utility = new ScreenUtility(this);
screenx = utility.getWidth();
screeny = utility.getHeight();
screenpixelx = utility.getPixelWidth();
screenpixely = utility.getPixelHeight();
MyFragment frag = new MyFragment();
getFragmentManager().beginTransaction()
.add(R.id.myContainer, frag)
.commit();
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
ScreenUtility utility = new ScreenUtility(this);
String output = "Width: " + utility.getWidth() + ", " +
"Height: " + utility.getHeight();
return true;
}
return super.onOptionsItemSelected(item);
}
}

Add the following to your fragment RelativeLayout. This should be as follows:
android:layout_width="match_parent"
android:layout_height="500dp"
For example the map layout fragment should be as follows :
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="500dp"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
android:paddingBottom="#dimen/activity_vertical_margin" tools:context=".MainActivity"
>
<com.google.android.gms.maps.MapView
android:id="#+id/map"
android:name="com.google.android.gms.maps.SupportMapFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentEnd="true"
android:layout_alignParentTop="true" />
</RelativeLayout>
Then add this fragment layout in the main layout.

put these in your listview too:
android:layout_width="match_parent"
android:layout_height="match_parent"
or you can change the layoutparameters to match_parent in yout fragment
that contains the listview.

you have to set the fragment container height to match parent not ListView. in your case ,ListView will fill it's parent height. ListView's parent is RelativeLayout and the RelativeLayout height is matchParent that means , RelativeLayout will also fill it's container and it's container is your fragment place holder that defined in your activity's layout file. you have to set that container's height to matchParent.

I think the problem is that you are trying to add fragment to ScrollView. use FrameLayout with android:layout_height=match_parent for fragment's container and if you have to add multiple fragments, then define multiple FrameLayouts in your activity's layout or add them dynamically.