I'm a beginner to the android development. I have an android image view that import web image by using Picasso 2.5.2 library. It's working. After click on that imageview, I want to create a full screen Android dialog with that image. I' used following code for it. But after click on the image view, a dialog is displayed without full screen. Finally, I want to zoom in and zoom out that full screen dialog. I want this kind of full screen on imageview onClickListener. Also see how the below image has a title and I also need the image caption (like in Facebook)
Here is my code
Mainactivity.java
import android.app.Dialog;
import android.content.Context;
import android.content.DialogInterface;
import android.graphics.Bitmap;
import android.graphics.drawable.ColorDrawable;
import android.graphics.drawable.Drawable;
import android.net.Uri;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.view.Window;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import com.squareup.picasso.Picasso;
public class MainActivity extends AppCompatActivity {
ImageView imageView1;
Context context;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initUi();
}
public void initUi(){
imageView1 = (ImageView)findViewById(R.id.image);
Picasso.with(this)
.load(Uri.parse("http://p.qpic.cn/videoyun/0/2449_43b6f696980311e59ed467f22794e792_1/640"))
.into(imageView1);
imageView1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
showImage();
}
});
}
public void showImage() {
Dialog builder = new Dialog(this, android.R.style.Theme_Light);
builder.requestWindowFeature(Window.FEATURE_NO_TITLE);
builder.getWindow().setBackgroundDrawable(
new ColorDrawable(android.graphics.Color.TRANSPARENT));
builder.setOnDismissListener(new DialogInterface.OnDismissListener() {
#Override
public void onDismiss(DialogInterface dialogInterface) {
//nothing;
}
});
ImageView imageView = new ImageView(this);
Picasso.with(this)
.load(Uri.parse("http://p.qpic.cn/videoyun/0/2449_43b6f696980311e59ed467f22794e792_1/640"))
.into(imageView);
builder.addContentView(imageView, new RelativeLayout.LayoutParams(
ViewGroup.LayoutParams.WRAP_CONTENT,
ViewGroup.LayoutParams.WRAP_CONTENT));
builder.show();
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/activity_add_info_other"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
android:orientation="vertical">
<ScrollView
android:layout_width="match_parent"
android:layout_height="wrap_content">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<TextView
android:text="Image buttons"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="5dp"
android:textColor="#android:color/black"
android:textSize="16sp"/>
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/image"/>
</LinearLayout>
</ScrollView>
</LinearLayout>
You can use Chrisbane's PhotoView lib for zooming the image.
Open the detail page by sending the path,
public void showImage() {
Intent intent = new Intent(this, ImageDeatilActvity.class);
intent.putExtra("path", "http://p.qpic.cn/videoyun/0/2449_43b6f696980311e59ed467f22794e792_1/640");
startActivity(intent);
}
Complete ImageDeatilActvity.java
public class ImageDeatilActvity extends AppCompatActivity implements View.OnSystemUiVisibilityChangeListener {
private boolean mIsFullScreen;
private Toolbar mToolbar;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_image_deatil_actvity);
mToolbar = (Toolbar) findViewById(R.id.toolbar);
if (mToolbar != null) {
setSupportActionBar(mToolbar);
}
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
final Drawable upArrow = ContextCompat.getDrawable(this, R.drawable.abc_ic_ab_back_material);
upArrow.setColorFilter(Color.WHITE, PorterDuff.Mode.SRC_ATOP);
getSupportActionBar().setHomeAsUpIndicator(upArrow);
mIsFullScreen = true;
String path = getIntent().getStringExtra("path");
PhotoView photoView = (PhotoView) findViewById(R.id.photo_view);
photoView.setOnPhotoTapListener(new PhotoViewAttacher.OnPhotoTapListener() {
#Override
public void onPhotoTap(View view, float x, float y) {
updateView();
}
#Override
public void onOutsidePhotoTap() {
updateView();
}
});
Glide.with(this).load(path).into(photoView);
}
#Override
public void onSystemUiVisibilityChange(int visibility) {
if ((visibility & View.SYSTEM_UI_FLAG_FULLSCREEN) == 0) {
mIsFullScreen = false;
}
updateView();
}
public void updateView() {
mIsFullScreen = !mIsFullScreen;
if (mIsFullScreen) {
hideSystemUI();
} else {
showSystemUI();
}
}
private void hideSystemUI() {
mToolbar.animate().translationY(-mToolbar.getHeight()).setInterpolator(new AccelerateInterpolator(2)).start();
}
private void showSystemUI() {
mToolbar.animate().translationY(0).setInterpolator(new DecelerateInterpolator(2)).start();
}
public int getStatusBarHeight() {
int result = 0;
int resourceId = getResources().getIdentifier("status_bar_height", "dimen", "android");
if (resourceId > 0) {
result = getResources().getDimensionPixelSize(resourceId);
}
return result;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
finish();
return true;
}
return super.onOptionsItemSelected(item);
}
}
Detail Activity Layout,
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="in.muthu.stackoverflow.ImageDeatilActvity">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:layout_alignParentTop="true"
android:background="#33000000"
android:fitsSystemWindows="true"
app:contentScrim="#android:color/transparent"
app:popupTheme="#style/AppTheme.AppBarOverlay"/>
<uk.co.senab.photoview.PhotoView
android:id="#+id/photo_view"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</RelativeLayout>
In My example, I am using Glide not Picaso, because Android
official recommendation is Glide, If you want you can change that.
set image to centre crop and resize it with your screen size like
Picasso.with(MainActivity.this)
.load(Uri.parse("http://p.qpic.cn/videoyun/0/2449_43b6f696980311e59ed467f22794e792_1/640"))
.noFade()
.resize(800, 800)
.centerCrop()
.into(imageView);
Use below xml for layout, i added one more ImageView just use make the visibility visible on click of small image_view
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/activity_add_info_other"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
android:orientation="vertical">
<ScrollView
android:layout_width="match_parent"
android:layout_height="wrap_content">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<TextView
android:text="Image buttons"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="5dp"
android:textColor="#android:color/black"
android:textSize="16sp"/>
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/image"/>
</LinearLayout>
</ScrollView>
<ImageView
android:layout_width="match_parent"
android:layout_height="match_parent"
/>
</RelativeLayout>
Related
error : "Attempt to invoke virtual method 'void android.widget.LinearLayout.addView(android.view.View)' on a null object reference"
so what should ı do to fix it if someone help me ı'll be so gratefull
here is my codes
cardbg.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="75dp"
android:background="#color/purple_500"
android:id="#+id/cardbg">
</LinearLayout>
activit_ymain.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayoutxmlns:android="http://schemas.android.com/apk/res/android"xmlns:app="http://schemas.android.com/apk/res-auto"xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<androidx.core.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="wrap_content"
tools:ignore="MissingConstraints">
<LinearLayout
android:id="#+id/main"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
android:orientation="vertical" />
</androidx.core.widget.NestedScrollView>
</androidx.constraintlayout.widget.ConstraintLayout>
MainActivity.java
package com.thehuman.todo;
import androidx.appcompat.app.AppCompatActivity;
import android.annotation.SuppressLint;
import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.LinearLayout;
public class MainActivity extends AppCompatActivity {
LinearLayout main;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
main = findViewById(R.id.main);
card first = new card(MainActivity.this);
main.addView(first);
}
}
class card extends LinearLayout{
card self;
LinearLayout bg,main;
Button clon,delete;
#SuppressLint("ResourceAsColor")
public card(Context context) {
super(context);
self=this;
main = findViewById(R.id.main);
bg = findViewById(R.id.cardbg);
clon = new Button(context);
clon.setBackgroundColor(R.color.white);
clon.setPadding(20,20,20,20);
clon.setTextColor(R.color.teal_200);
clon.setText("clon me");
delete = new Button(context);
delete.setBackgroundColor(R.color.black);
delete.setTextColor(R.color.teal_200);
delete.setPadding(20,20,20,20);
delete.setText("delete me");
bg.addView(clon);
bg.addView(delete);
clon.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
card cloncard = new card(context);
main.addView(cloncard);
}
});
delete.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
main.removeView(self);
}
});
}
}
I suppose you are getting null object reference error in class Card. Because you are using bg = findViewById(R.id.cardbg);. You can not find cardbg.xml using findViewById because cardbg.xml have not been attached to you activity layout. You have to inflate your xml by yourself using an inflater.
Use
bg = LayoutInflater.from(context).inflate(R.layout.cardbg, null).findViewById(R.id.cardbg);
I created a top app bar by using the Material Components(Android), and changed the navigation icon from the menu icon to an arrow icon. The on click event is back to the previous page. I have already read through the official docs and it doesn't work in my case. I have no idea how to set on click event for that arrow icon. Any help is appreciated.
A better image to understand what I am talking
Click me
Link of the docs Click me
settingsActivity.java
package studio.itztaylorau.dashboard;
import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
import androidx.preference.PreferenceFragmentCompat;
import studio.itztaylorau.dashboard.R;
import studio.itztaylorau.dashboard.AccountActivity;
public class SettingsActivity extends AppCompatActivity{
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.settings_activity);
if (savedInstanceState == null) {
getSupportFragmentManager()
.beginTransaction()
.replace(R.id.settings, new SettingsFragment())
.commit();
}
View topAppBar = findViewById(R.id.topAppBar);
topAppBar.setNavigationOnClickListener {
Intent i = new Intent(getApplicationContext(), Account.class);
startActivity(i);
}
}
public static class SettingsFragment extends PreferenceFragmentCompat {
#Override
public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
setPreferencesFromResource(R.xml.root_preferences, rootKey);
}
}
}
settingsActivity.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto">
<FrameLayout
android:id="#+id/settings"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<com.google.android.material.appbar.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<com.google.android.material.appbar.MaterialToolbar
android:id="#+id/topAppBar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:title="#string/topAppBarTitle_Settings"
android:background="#color/appTopBar"
app:navigationIcon="#drawable/ic_baseline_arrow_back_24"
/>
</com.google.android.material.appbar.AppBarLayout>
</FrameLayout>
</LinearLayout>
You're making a fragment transaction on the settings FrameLayout placeholder, but this placeholder also contains the AppBarLayout of the toolbar.
To solve this:
Step 1: Get the AppBarLayout out of the Fragment FrameLayout placeholder, So, change the layout to:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<com.google.android.material.appbar.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<com.google.android.material.appbar.MaterialToolbar
android:id="#+id/topAppBar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="#color/appTopBar"
app:navigationIcon="#drawable/ic_baseline_arrow_back_24"
app:title="#string/topAppBarTitle_Settings" />
</com.google.android.material.appbar.AppBarLayout>
<FrameLayout
android:id="#+id/settings"
android:layout_width="match_parent"
android:layout_height="match_parent">
</FrameLayout>
</LinearLayout>
Step 2: Instead of topAppBar.setNavigationOnClickListener, use topAppBar.setOnClickListener
View topAppBar = findViewById(R.id.topAppBar);
topAppBar.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent i = new Intent(getApplicationContext(), Account.class);
startActivity(i);
}
});
I created a page where it will show the firebase data in a RecyclerView. It work but I decided to put a toolbar at the top of the page to have a back function. After I put the toolbar in my layout file, the RecyclerView is not showing any data anymore. I think that my layout XML file is wrong. Thanks in advance for anyone helping.
Actity file
package com.example.attendanceappvqyfyp;
import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.Toolbar;
import com.example.attendanceappvqyfyp.Interface.itemClickListener;
import com.example.attendanceappvqyfyp.Common.Common;
import com.example.attendanceappvqyfyp.Model.LecturerClass;
import com.example.attendanceappvqyfyp.Model.News;
import com.example.attendanceappvqyfyp.Model.Timetable;
import com.firebase.ui.database.FirebaseRecyclerAdapter;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.example.attendanceappvqyfyp.Common.Common;
public class LecturerClassList extends AppCompatActivity {
RecyclerView recyclerView;
RecyclerView.LayoutManager layoutManager;
FirebaseDatabase database;
DatabaseReference lecturerclass;
DatabaseReference news;
FirebaseRecyclerAdapter<LecturerClass,LecturerClassViewHolder> adapter;
TextView newscourse, newsclass;
EditText newsdescription;
Toolbar toolbar;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_lecturer_class_list);
//Firebase
database = FirebaseDatabase.getInstance();
lecturerclass = database.getReference("Class");
news = database.getReference("News");
recyclerView = (RecyclerView)findViewById(R.id.recycler_lecturerclass);
recyclerView.setHasFixedSize(true);
layoutManager = new LinearLayoutManager(this);
recyclerView.setLayoutManager(layoutManager);
//Toolbar code
toolbar = findViewById(R.id.toolbar);
toolbar.setTitle("Class List");
toolbar.setNavigationIcon(R.drawable.ic_arrow_back_black_24dp);
loadLecturerClass(Common.currentLecturer.getName());
}
private void loadLecturerClass(String Lecturer) {
adapter = new FirebaseRecyclerAdapter<LecturerClass, LecturerClassViewHolder>(LecturerClass.class, R.layout.lecturerclass_item, LecturerClassViewHolder.class, lecturerclass.orderByChild("lecturer").equalTo(Lecturer)) {
#Override
protected void populateViewHolder(LecturerClassViewHolder lecturerClassViewHolder, LecturerClass lecturerClass, int i) {
lecturerClassViewHolder.lclasstitle.setText("Class :" + adapter.getRef(i).getKey());
lecturerClassViewHolder.ldate.setText("Day :" + lecturerClass.getDay());
lecturerClassViewHolder.ltime.setText("Time :" + lecturerClass.getTime());
lecturerClassViewHolder.lclassroom.setText("Classroom :" + lecturerClass.getClassroom());
lecturerClassViewHolder.lcourse.setText(lecturerClass.getCourse());
lecturerClassViewHolder.setItemClickListener(new itemClickListener() {
#Override
public void onClick(View view, int position, boolean isLongClick) {
//code later
}
});
}
};
recyclerView.setAdapter(adapter);
}
#Override
public boolean onContextItemSelected(MenuItem item) {
if(item.getTitle().equals(Common.News))
{
showNewsDialog(adapter.getRef(item.getOrder()).getKey(),adapter.getItem(item.getOrder()));
}
return super.onContextItemSelected(item);
}
private void showNewsDialog(final String course, final LecturerClass item) {
AlertDialog.Builder alertDialog = new AlertDialog.Builder(LecturerClassList.this);
alertDialog.setTitle("Make Announcement");
alertDialog.setMessage("Make announcement about this class.");
LayoutInflater inflater = this.getLayoutInflater();
View lecturer_make_news = inflater.inflate(R.layout.activity_lecturer_make_news, null);
newscourse = lecturer_make_news.findViewById(R.id.NewsCourse);
newsclass = lecturer_make_news.findViewById(R.id.NewsClass);
newsdescription = lecturer_make_news.findViewById(R.id.NewsDescription);
newscourse.setText("Course: "+item.getCourse());
newsclass.setText("Subject: " + course);
alertDialog.setView(lecturer_make_news);
alertDialog.setPositiveButton("Post", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int i) {
if(newsdescription.getText().toString().isEmpty()){
Toast.makeText(LecturerClassList.this, "Post cancel, description cannot be empty.", Toast.LENGTH_SHORT).show();
}
else {
News lnews = new News(
item.getCourse(),
course,
newsdescription.getText().toString()
);
news.child(String.valueOf(System.currentTimeMillis())).setValue(lnews);
Toast.makeText(LecturerClassList.this, "Announcement post successfully.", Toast.LENGTH_SHORT).show();
finish();
}
}
});
alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();;
}
});
alertDialog.show();
}
}
Activity file for viewholder
package com.example.attendanceappvqyfyp;
import android.view.ContextMenu;
import android.view.View;
import android.widget.TextView;
import com.example.attendanceappvqyfyp.Common.Common;
import androidx.recyclerview.widget.RecyclerView;
import com.example.attendanceappvqyfyp.Interface.itemClickListener;
public class LecturerClassViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener,View.OnCreateContextMenuListener {
public TextView lclasstitle, ldate, ltime, lclassroom, lcourse;
private itemClickListener itemClickListener;
public LecturerClassViewHolder(View itemView) {
super(itemView);
lclasstitle = (TextView)itemView.findViewById(R.id.lclasstitle);
ldate = (TextView)itemView.findViewById(R.id.ldate);
ltime = (TextView)itemView.findViewById(R.id.ltime);
lclassroom = (TextView)itemView.findViewById(R.id.lclassroom);
lcourse = (TextView)itemView.findViewById(R.id.lcourse);
itemView.setOnCreateContextMenuListener(this);
itemView.setOnClickListener(this);
}
public void setItemClickListener(itemClickListener itemClickListener) {
this.itemClickListener = itemClickListener;
}
#Override
public void onClick(View view) {
itemClickListener.onClick(view, getAdapterPosition(), false);
}
public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
menu.setHeaderTitle("Select");
menu.add(0,0,getAdapterPosition(), Common.News);
}
}
Layout file for recyclerview
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".LecturerClassList">
<android.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="?attr/colorPrimary"
android:minHeight="?attr/actionBarSize"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:theme="#style/ThemeOverlay.AppCompat.Dark" />
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/recycler_lecturerclass"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:scrollbars="vertical"
app:layout_constraintTop_toBottomOf="#+id/toolbar" />
</androidx.constraintlayout.widget.ConstraintLayout>
Layout file for itemview
<?xml version="1.0" encoding="utf-8"?>
<androidx.cardview.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="160dp"
app:cardElevation="4dp"
android:layout_marginBottom="8dp"
>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="#+id/lclasstitle"
android:layout_width="match_parent"
android:layout_height="40dp"
android:gravity="center"
android:text=""
android:textColor="#android:color/black"
android:textSize="20sp" />
<TextView
android:id="#+id/ldate"
android:layout_width="match_parent"
android:layout_height="40dp"
android:layout_alignBottom="#id/lclasstitle"
android:layout_marginBottom="-40dp"
android:gravity="center"
android:text=""
android:textColor="#android:color/black"
android:textSize="20sp" />
<TextView
android:id="#+id/ltime"
android:layout_width="match_parent"
android:layout_height="40dp"
android:layout_alignBottom="#id/ldate"
android:layout_marginBottom="-40dp"
android:gravity="center"
android:text=""
android:textColor="#android:color/black"
android:textSize="20sp" />
<TextView
android:id="#+id/lclassroom"
android:layout_width="match_parent"
android:layout_height="40dp"
android:layout_alignParentBottom="true"
android:gravity="center"
android:text=""
android:textColor="#android:color/black"
android:textSize="20sp" />
<TextView
android:id="#+id/lcourse"
android:layout_width="match_parent"
android:layout_height="40dp"
android:layout_alignParentBottom="true"
android:gravity="center"
android:text=""
android:visibility="invisible"
android:textColor="#android:color/black"
android:textSize="20sp" />
</RelativeLayout>
</androidx.cardview.widget.CardView>
Thanks to ZeePee for giving this link Display Back Arrow on Toolbar, although the toolbar didnt work for me, i change it back to actionbar and use the code from the link and it work.
Try adding horizontal constraints for Toolbar and Recycler View. After that you need to specify where do you want your single item widgets in Relative layout
iam new to android development and here iam trying to change images on a button click ,iam using the animate() method to fade one of the images and achieve the result .The first button click is fading the images but the second time i click on this button ,it doesnt give any result (images doesnt fade ) .
give me any possible solutions.thankyou
.java file
package e.nani.bestimage;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageView;
public class MainActivity extends AppCompatActivity {
public void change(View view) {
int flag=0;
ImageView img1 = (ImageView) findViewById(R.id.single);
ImageView img2 = (ImageView) findViewById(R.id.withands);
switch(flag){
case 0:img1.animate().alpha(0f).setDuration(2000);
img2.animate().alpha(1f).setDuration(2000);
flag=1;
break;
case 1: img1.animate().alpha(1f).setDuration(2000);
img2.animate().alpha(0f).setDuration(2000);
flag=0;
break;
}
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ImageView img1=(ImageView) findViewById(R.id.single);
ImageView img2=(ImageView) findViewById(R.id.withands);
img1.animate().alpha(1f).setDuration(2000);
img2.animate().alpha(0f).setDuration(2);
}
}
xml file
<?xml version="1.0" encoding="utf-8"?>
<android.widget.RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#android:color/holo_purple"
tools:context=".MainActivity">
<ImageButton
android:id="#+id/single"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:scaleType="centerCrop"
app:srcCompat="#drawable/imgthree" />
<ImageView
android:id="#+id/withands"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:clickable="true"
app:srcCompat="#drawable/imgsix" />
<Button
android:id="#+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="98dp"
android:alpha="0.7"
android:background="#android:color/background_dark"
android:onClick="change"
android:text="find out the person"
android:textColor="#android:color/holo_blue_bright" />
</android.widget.RelativeLayout>
Anytime the change() method is called it's setting the flag equals to 0. Try this :
public class MainActivity extends AppCompatActivity {
int flag;
public void change(View view) {
ImageView img1 = (ImageView) findViewById(R.id.single);
ImageView img2 = (ImageView) findViewById(R.id.withands);
switch(flag){
case 0:
img1.animate().alpha(0f).setDuration(2000);
img2.animate().alpha(1f).setDuration(2000);
flag=1;
break;
case 1:
img1.animate().alpha(1f).setDuration(2000);
img2.animate().alpha(0f).setDuration(2000);
flag=0;
break;
}
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
flag = 0;
ImageView img1=(ImageView) findViewById(R.id.single);
ImageView img2=(ImageView) findViewById(R.id.withands);
img1.animate().alpha(1f).setDuration(2000);
img2.animate().alpha(0f).setDuration(2);
}
}
I started learning making Android Apps, and I have stumbled upon a problem.
I have made my app to change an imageView by a button
button = (Button)findViewById(R.id.bttOK);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
imageView.setImageResource(R.drawable.ring); // changes the image
so, now, when I click on the button, it changes an image.
The problem is, the original image was centered, and the image that replaces it is set on top left. I can't center it, or move it or anything. I guess I am missing a tiny detail somewhere.
MainActivity.java:
package com.maxa.testaplikacija;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity {
TextView text;
Button button;
ImageView imageView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
imageView = findViewById(R.id.imageView);
button = (Button)findViewById(R.id.bttOK);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
imageView.setImageResource(R.drawable.ring);
}
});
}
}
activity_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="16dp"
android:paddingLeft="16dp"
android:paddingRight="16dp"
android:paddingTop="16dp"
tools:context=".MainActivity">
<TextView
android:id="#+id/udajSe"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_above="#+id/bttOK"
android:layout_centerHorizontal="true"
android:text="#string/udaj_se_za_mene" />
<ImageView
android:id="#+id/imageView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_marginTop="23dp"
android:adjustViewBounds="false"
android:contentDescription="#string/poklon"
android:foregroundGravity="center_horizontal"
app:srcCompat="#drawable/present" />
<Button
android:id="#+id/bttOK"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="115dp"
android:text="#string/otvori_me" />
</RelativeLayout>
I am still new to this, but I am a quick learner.
Inside the onclick method align the imageView like this
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
params.addRule(RelativeLayout.CENTER_HORIZONTAL, RelativeLayout.TRUE);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
imageView.setImageResource(R.drawable.ring);
imageView.setLayoutParams(params);
}
});
Your view seems to have the image set to top left, see these XML tags in your ImageView:
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
Are you sure the original image files aren't spaced differently / have extra padding as part of the image itself?