Develop Reference

[Android]onTouch in child View is not responding

I have been working on making Sudoku grid whose cell's value changes whenever I touch on a cell. So I have implemented this sudoku grid in a LinearLayout by Child View, and tried using OnTouch method, but it is not working. I tried using log method to check whether onTouch is actually called, but it seemes that this method is perfectly ignored. I have been searching for solutions on other question, but it seems none of those solutions helped. I feel kinda suck here, and any help would be greatly appreciated.
Here is my code:
SudokuActivity.java
package snacker.nonogramsolver;
import ...; /*many things are imported here*/
public class SudokuActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_sudoku);
Button btn = (Button)findViewById(R.id.btn_clear);
Sudoku sdk = new Sudoku(this);
sdk.setOnTouchListener(sdk);
}
}
;
Sudoku.java
package snacker.nonogramsolver;
import ...;
public class Sudoku extends View implements View.OnTouchListener {
int mWidth = 9;
int mHeight = 9;
int mCellWidth, mCellHeight;
int mCellMargin;
int mEdgeThick;
int mStatus;
int mTextSize;
int mXNow = -1, mYNow = -1;
int[][] mBoard = new int[9][9];
Point mBoardPt;
Paint mTextPaint, mTileEdgePaint;
final static int VALID = 0;
public Sudoku(Context context){
super(context);
initializeBoard();
}
public Sudoku(Context context, AttributeSet attrs){
super(context, attrs);
initializeBoard();
}
#Override
protected void onDraw(Canvas canvas){
/* There are some codes here */
Log.d("LogTest","OnDraw Complete");
}
public void initializeBoard(){
for (int x=0; x< mWidth; x++){
for (int y=0; y< mHeight; y++){
mBoard[x][y] = 0;
}
}
invalidate();
}
public boolean onTouch(View v, MotionEvent event){
Log.d("LogTest","Touched?"); /* LOG NOT ACTIVE HERE */
if(event.getAction() == MotionEvent.ACTION_DOWN){
mXNow = getBoardX(event.getX());
Log.d("LogTest","" + mXNow); /* LOG NOT ACTIVE HERE */
mYNow = getBoardY(event.getY());
Log.d("LogTest","" + mYNow); /* LOG NOT ACTIVE HERE */
mBoard[mXNow][mYNow] = mBoard[mXNow][mYNow] + 1;
invalidate();
return true;
}
else return false;
}
int getBoardX(float scrx){
int x = (int)((scrx) / mCellWidth);
if (x < 0) x = 0;
if (x > 8) x= 8;
return x;
}
int getBoardY(float scry){
int y = (int)((scry) / mCellHeight);
if (y < 0) y = 0;
if (y > 8) y = 8;
return y;
}
}
Edit: added activity XML file.
<?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:orientation="vertical"
android:id="#+id/activity_sudoku"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context="snacker.nonogramsolver.SudokuActivity">
<snacker.nonogramsolver.Sudoku
android:id="#+id/SudokuGrid"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<Button
android:id="#+id/btn_clear"
android:layout_width="150dp"
android:layout_height="30dp"
android:layout_weight="0.06"
android:text="Clear" />
</LinearLayout>

You cannot directly add touchListener by just creating object of
Sudoku class. You should add view in xml or programatically.
Your Activity
public class MyActivity extends Activity{
#Override
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
//initializing custom views
MyCustomView1 myCustomView1 = new MyCustomView1(parameterList);
MyCustomView2 myCustomView2 = new MyCustomView2(parameterList);
//adding both custom views to the main activity
mainView.addView(myCustomView1);
mainView.addView(myCustomView1);
//adding custom listener to the custom view 1
myCustomView1.setCustomEventListener(new OnCustomEventListener() {
#Override
public void onEvent() {
//firing an event of custom view 1
Toast.makeText(MainActivity.this, "Touched custom view 1",
Toast.LENGTH_SHORT).show();
}
});
//adding custom listener to the custom view 2
myCustomView2.setCustomEventListener(new OnCustomEventListener() {
#Override
public void onEvent() {
//firing an event of custom view 2
Toast.makeText(MainActivity.this, "Touched custom view 2",
Toast.LENGTH_SHORT).show();
}
});
}
}
Your CustomView 1
public class MyCustomView1 extends LinearLayout{
OnCustomEventListener myCustomEventListener;
public MyCustomView1(ParameterList){
super(ContextFromParameterList);
//Just adding something to the custom view 1 in order to distinguish it on the screen
TextView tv = new TextView(ContextFromParameterList);
tv.setText("Hello world from custom view 1");
addView(tv);
this.setOnTouchListener(new OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
//delegating one event to another (delegating touch event to custom event)
if (MyCustomView1.this.myCustomEventListener != null)
MyCustomView1.this.myCustomEventListener.onEvent();
return false;
}
}); }
public void setCustomEventListener(OnCustomEventListener
eventListener) {
//setting custom listener from activity
myCustomEventListener = eventListener; } }
Your CustomView2
public class MyCustomView2 extends LinearLayout {
OnCustomEventListener myCustomEventListener;
public MyCustomView2(ParameterList) {
super(ContextFromParameterList);
//Just adding something to the custom view 1 in order to distinguish it on the screen
TextView tv = new TextView(ContextFromParameterList);
tv.setText("Hello world from custom view 2");
addView(tv);
this.setOnTouchListener(new OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
//delegating one event to another (delegating touch event to custom event)
if (MyCustomView2.this.myCustomEventListener != null)
MyCustomView2.this.myCustomEventListener.onEvent();
return false;
}
});
}
public void setCustomEventListener(OnCustomEventListener eventListener) {
//setting custom listener from activity
myCustomEventListener = eventListener;
}
}
Your listener interface:
public interface OnCustomEventListener{
//interface defines one method. Can be more and methods may have parameters
public void onEvent();
}

How to add a custom view in another custom view in Android?

I want to create a custom view which should be added in another custom view.
The second view will be a container, so it should be able to contain the first view as its child.
For creating this views I am extending ViewGroup & LinearLayout classes.
Child view class is NodeView
public class NodeView extends LinearLayout
{
private final static String TAG = "NodeView";
private ImageView ivTop;
private ImageView ivBottom;
private Context myContext;
public NodeView(Context context, AttributeSet attrs)
{
super(context, attrs);
this.myContext = context;
setOrientation(LinearLayout.VERTICAL);
setGravity(Gravity.CENTER);
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
inflater.inflate(R.layout.view_test_multi, this, true);
ivTop = (ImageView) getChildAt(0);
ivBottom = (ImageView) getChildAt(2);
ivTop.setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View v)
{
Toast.makeText(myContext, "Top Clicked", Toast.LENGTH_SHORT).show();
}
});
ivBottom.setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View v)
{
Toast.makeText(myContext, "Bottom Clicked", Toast.LENGTH_SHORT).show();
}
});
}
#Override
protected void onDraw(Canvas canvas)
{
super.onDraw(canvas);
}
public NodeView(Context context)
{
this(context, null);
}
}
& the container class is TreeViewGroup
public class TreeViewGroup extends ViewGroup
{
private static final String TAG = "CustomTreeNodeView";
NodeView nodeView;
public TreeViewGroup(Context context, AttributeSet attrs, int defStyleAttr)
{
super(context, attrs, defStyleAttr);
nodeView = new NodeView(getContext());
addView(nodeView);
}
public TreeViewGroup(Context context, AttributeSet attrs)
{
this(context, attrs, 0);
}
public TreeViewGroup(Context context)
{
this(context, null, 0);
}
#Override
protected void onDraw(Canvas canvas)
{
super.onDraw(canvas);
}
#Override
protected void onLayout(boolean changed, int l, int t, int r, int b)
{
}
}
& xml layout for node view is view_test_multi.xml
<?xml version="1.0" encoding="utf-8"?>
<merge xmlns:android="http://schemas.android.com/apk/res/android" >
<ImageView
android:layout_width="15dp"
android:layout_height="15dp"
android:layout_centerVertical="true"
android:src="#drawable/point_grey" />
<ImageView
android:layout_width="35dp"
android:layout_height="35dp"
android:layout_centerVertical="true"
android:src="#drawable/point_red" />
<ImageView
android:layout_width="15dp"
android:layout_height="15dp"
android:layout_centerVertical="true"
android:src="#drawable/point_grey" />
</merge>
My activity's layout is activity_main.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:custom="http://schemas.android.com/apk/res/com.ab1209.testcustom"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<com.ab1209.testcustom.view.TreeViewGroup
android:id="#+id/activity_main_custom_tree_node_view"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</RelativeLayout>
MainActivity class is
**public class MainActivity extends Activity
{
TreeViewGroup treeNodeView;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
treeNodeView = (TreeViewGroup) findViewById(R.id.activity_main_custom_tree_node_view);
}
}**
When I run the app I don't see the NodeView added in main View. Am I doing the right thing if not please tell me how can I make it working?

To create a custom ViewGroup, the only method you need to override is
onLayout. The onLayout is triggered after the ViewGroup itself has
finished laying itself out inside its own container ViewGroup and is
now responsible for laying out its children. It should call the layout
method on all of its children to now position and size them (the left
and top parameters will determine the child view’s x and y and the
right and bottom will determine its width (right – left) and height
(top-bottom).
So your TreeViewGroup code will look like :
#Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
int count = getChildCount();
for (int i = 0; i < count; i++) {
View child = getChildAt(i);
if (child.getVisibility() != GONE) {
ViewGroup.LayoutParams lp = (ViewGroup.LayoutParams) child
.getLayoutParams();
int childLeft = 0;
int childTop = 0;
child.layout(childLeft, childTop,
childLeft + child.getMeasuredWidth(),
childTop + child.getMeasuredHeight());
}
}
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
measureChildren(widthMeasureSpec, heightMeasureSpec);
int measuredWidth = 200; // Calculate the height
int measuredHeight = 200; // Calculate the width
setMeasuredDimension(measuredWidth, measuredHeight);
}
Refer this link http://arpitonline.com/2012/07/01/creating-custom-layouts-for-android/

Adding a Custom View as header of ListView

I have a custom view (a class extending View) that I'd like to add as a header of List View. Here's the code snippet:
public class MyActivity extends RoboListActivity {
...
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
View header = getLayoutInflater().inflate(R.layout.myactivity_apps_header, null);
getListView().addHeaderView(header);
...more code
}
But, I can't see anything. But, when I tried to add a non-custom view, it works. Am I missing something, please guide
Providing Complete Source Code
Custom View
public class SpaceCustomView extends View {
private Paint mPaint;
private Paint mTextPaint;
private final String mMessage = "Foo Bar";
private Rect mBounds;
public StorageSpaceCustomView(Context context) {
super(context);
initInput();
}
public StorageSpaceCustomView(Context context, AttributeSet attrs) {
super(context, attrs, 0);
initInput();
}
public StorageSpaceCustomView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
initInput();
}
#Override
public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
setMeasuredDimension(widthMeasureSpec, heightMeasureSpec);
}
#Override
public void onDraw(android.graphics.Canvas canvas) {
canvas.drawRect(30, 30, 800, 80, mPaint);
canvas.drawText(mMessage, 30, 60, mTextPaint);
}
private void initInput() {
mBounds = new Rect();
mPaint = new Paint();
mPaint.setColor(Color.RED);
mPaint.setStyle(Paint.Style.FILL_AND_STROKE);
mTextPaint = new Paint();
mTextPaint.setColor(Color.BLACK);
mTextPaint.setTextAlign(Paint.Align.LEFT);
mTextPaint.setTextSize(20);
mTextPaint.getTextBounds(mMessage, 0, mMessage.length(), mBounds);
}
}
Header Layout XML
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<com.mycompany.app.view.custom.SpaceCustomView
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>
Activity Class
public class AppsActivity extends RoboListActivity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//add header and footer views
View header = getLayoutInflater().inflate(R.layout.activity_apps_header, null);
getListView().addHeaderView(header);
View footer = getLayoutInflater().inflate(R.layout.activity_pps_footer, null);
getListView().addFooterView(footer);
List<AppInfo> applicationList = Mycatalog.getPromotions();
AppListAdapter adapter = new AppListAdapter(this, applicationList);
setListAdapter(adapter);
}
private class AppListAdapter extends ArrayAdapter<AppInfo> {
public AppListAdapter(Activity activity, List<AppInfo> apps) {
super(activity, android.R.layout.simple_list_item_1, apps);
}
#Override
public boolean isEmpty(){
return false;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
// if we weren't given a view, inflate one
if (null == convertView) {
convertView = getLayoutInflater()
.inflate(R.layout.activity_uninstall_apps, null);
}
return convertView;
}
}
}
Conclusion: I can see the footer but not the header.

ListView shows headers and footers only when it's Adapter's isEmpty() returns false.
So try setting an adapter that does that...

Making canvas background as XML layout

I have an XML layout. I want to draw a line after getting the button clicked. I made an inner class to accomplish it. But when it do so my content view get changed to canvas of View class.
I want my content view to be the same XML with the line I generated by clicking a Button.
Thank you.
Code:
public class Dots extends Activity implements View.OnClickListener
{
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_dots);
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 5; j++) {
b[i][j] = (Button) findViewById(refbutton[i][j]);
b[i][j].setOnClickListener(this);
}
}
}
private static class SampleView extends View
{
public SampleView(Context context)
{
super(context);
}
protected void onDraw(Canvas canvas)
{
Paint p = new Paint();
p.setColor(Color.BLACK);
p.setStyle(Paint.Style.STROKE);
canvas.drawLine(5, 5, 25, 5, p);
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
//getMenuInflater().inflate(R.menu.dots, menu);
return true;
}
#Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
SampleView d=new SampleView(this);
setContentView(d);
}
}

Carousel effect using android-supportv4.viewpager

I need an example of view pager with carousel effect.I've searched through internet but I couldn't find any example.So , have you done anything like this before ? Do you have any examples that I can examine.

You need:
activity_main
item
Custom Fragment
Custom LinearLayout
CustomPagerAdapter
Activity
I use this code:
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:attrs="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="#dimen/activity_vertical_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context="com.thedeveloperworldisyours.carouselviewpager.MainActivity">
<android.support.v4.view.ViewPager
android:id="#+id/activity_main_view_pager"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</RelativeLayout>
item
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:orientation="vertical">
<com.thedeveloperworldisyours.carouselviewpager.CustomLinearLayout
android:id="#+id/item_root"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#android:color/transparent"
android:gravity="center"
android:orientation="vertical">
<TextView
android:id="#+id/item_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="#dimen/item_size_text" />
<Button
android:id="#+id/item_content"
android:layout_width="230dp"
android:layout_height="120dp"
android:background="#android:color/black"/>
</com.thedeveloperworldisyours.carouselviewpager.CustomLinearLayout>
</LinearLayout>
Custom Fragment
public class CustomFragment extends Fragment {
public static Fragment newInstance(Activity context, int position, float scale) {
Bundle bundle = new Bundle();
bundle.putInt("position", position);
bundle.putFloat("scale", scale);
return Fragment.instantiate(context, CustomFragment.class.getName(), bundle);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
if (container == null) {
return null;
}
LinearLayout linearLayout = (LinearLayout)
inflater.inflate(R.layout.item, container, false);
int position = this.getArguments().getInt("position");
TextView textView = (TextView) linearLayout.findViewById(R.id.item_text);
textView.setText(String.valueOf(position));
CustomLinearLayout root = (CustomLinearLayout) linearLayout.findViewById(R.id.item_root);
float scale = this.getArguments().getFloat("scale");
root.setScaleBoth(scale);
return linearLayout;
}
}
Custom LinearLayout
public class CustomLinearLayout extends LinearLayout {
private float mScale = BIG_SCALE;
public CustomLinearLayout(Context context, AttributeSet attrs) {
super(context, attrs);
}
public CustomLinearLayout(Context context) {
super(context);
}
public void setScaleBoth(float scale) {
this.mScale = scale;
this.invalidate(); // If you want to see the mScale every time you set
// mScale you need to have this line here,
// invalidate() function will call onDraw(Canvas)
// to redraw the view for you
}
#Override
protected void onDraw(Canvas canvas) {
// The main mechanism to display mScale animation, you can customize it
// as your needs
int w = this.getWidth();
int h = this.getHeight();
canvas.scale(mScale, mScale, w / 2, h / 2);
super.onDraw(canvas);
}
}
The most import thing is the adapter
public class CustomPagerAdapter extends FragmentPagerAdapter implements ViewPager.PageTransformer {
public final static float BIG_SCALE = 1.0f;
public final static float SMALL_SCALE = 0.7f;
public final static float DIFF_SCALE = BIG_SCALE - SMALL_SCALE;
private Activity mContext;
private FragmentManager mFragmentManager;
private float mScale;
public CustomPagerAdapter(Activity context, FragmentManager fragmentManager) {
super(fragmentManager);
this.mFragmentManager = fragmentManager;
this.mContext = context;
}
#Override
public Fragment getItem(int position) {
// make the first mViewPager bigger than others
if (position == FIRST_PAGE)
mScale = BIG_SCALE;
else
mScale = SMALL_SCALE;
return CustomFragment.newInstance(mContext, position, mScale);
}
#Override
public int getCount() {
return PAGES;
}
#Override
public void transformPage(View page, float position) {
CustomLinearLayout myLinearLayout = (CustomLinearLayout) page.findViewById(R.id.item_root);
float scale = BIG_SCALE;
if (position > 0) {
scale = scale - position * DIFF_SCALE;
} else {
scale = scale + position * DIFF_SCALE;
}
if (scale < 0) scale = 0;
myLinearLayout.setScaleBoth(scale);
}
}
and now the Activity
public class MainActivity extends AppCompatActivity {
public final static int PAGES = 5;
public final static int FIRST_PAGE = 0 ;
public CustomPagerAdapter mAdapter;
public ViewPager mViewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mViewPager = (ViewPager) findViewById(R.id.activity_main_view_pager);
mAdapter = new CustomPagerAdapter(this, this.getSupportFragmentManager());
mViewPager.setAdapter(mAdapter);
mViewPager.setPageTransformer(false, mAdapter);
// Set current item to the middle page so we can fling to both
// directions left and right
mViewPager.setCurrentItem(FIRST_PAGE);
// Necessary or the mViewPager will only have one extra page to show
// make this at least however many pages you can see
mViewPager.setOffscreenPageLimit(3);
// Set margin for pages as a negative number, so a part of next and
// previous pages will be showed
mViewPager.setPageMargin(-400);
}
}
Also you check this Tutorial and this exmple in GitHub.

Please find the link below as solution to implement Carousel in android using View Pager:
https://github.com/haerulmuttaqin/SwipeViewPager
Hope it helps anyone looking for answers.

You can have a look at CarouselView.
Might help you if you need a simple carouselview.
Add view in your layout:
<com.synnapps.carouselview.CarouselView
android:id="#+id/carouselView"
android:layout_width="match_parent"
android:layout_height="200dp"
app:fillColor="#FFFFFFFF"
app:pageColor="#00000000"
app:radius="6dp"
app:slideInterval="3000"
app:strokeColor="#FF777777"
app:strokeWidth="1dp"/>
Add images by implementing callback:
public class SampleCarouselViewActivity extends AppCompatActivity {
CarouselView carouselView;
int[] sampleImages = {R.drawable.image_1, R.drawable.image_2, R.drawable.image_3, R.drawable.image_4, R.drawable.image_5};
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_sample_carousel_view);
carouselView = (CarouselView) findViewById(R.id.carouselView);
carouselView.setPageCount(sampleImages.length);
carouselView.setImageListener(imageListener);
}
ImageListener imageListener = new ImageListener() {
#Override
public void setImageForPosition(int position, ImageView imageView) {
imageView.setImageResource(sampleImages[position]);
}
};
}