I have a main Layout including 2 layout, one containing a FrameLayout with a Fragment inside. And the other one with a LinearLayout containing a ListView. This is how look my main layout :
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<ScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fillViewport="true">
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<include layout="#layout/map_layout" android:layout_height="wrap_content" android:layout_width="fill_parent" android:layout_weight="1"></include>
<include layout="#layout/list_layout" android:layout_height="wrap_content" android:layout_width="fill_parent" android:layout_weight="6"></include>
</LinearLayout>
</ScrollView>
</LinearLayout>
The first Fragment contain a map and the second contain a custom ListView with its own listAdapter.
So here my problem, I know it's kind of triky to put a ListView in a ScrollView. But in my onCreateView of my ListFragment.java I put this :
list.setOnTouchListener(new View.OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
v.getParent().requestDisallowInterceptTouchEvent(true);
return false;
}
});
But the ListView keep catch the scroll. At a moment, the ScrollView bug and put the map and le list down of an infite ScrollView.
How can I do to make it work ?
I finally find the solution of my problem.
I needed to extend my listView so there its only scrolled by the ScrollView. here the code I find :
Helper.java:
public class Helper {
public static void getListViewSize(ListView myListView) {
ListAdapter myListAdapter = myListView.getAdapter();
if (myListAdapter == null) {
//do nothing return null
return;
}
//set listAdapter in loop for getting final size
int totalHeight = 0;
for (int size = 0; size < myListAdapter.getCount(); size++) {
View listItem = myListAdapter.getView(size, null, myListView);
listItem.measure(0, 0);
totalHeight += listItem.getMeasuredHeight();
}
//setting listview item in adapter
ViewGroup.LayoutParams params = myListView.getLayoutParams();
params.height = totalHeight + (myListView.getDividerHeight() * (myListAdapter.getCount() - 1));
myListView.setLayoutParams(params);
}
}
and to implement it, you just need this line:
Helper.getListViewSize(myList);
I have found this solution here : http://www.androidhub4you.com/2012/12/listview-into-scrollview-in-android.html
Related
I have a page in which I'm taking the START TIME and END TIME from DATABASE.
Let's say the START TIME is 7:00 and END TIME is 22:00
I want to use this START TIME and END TIME to show in my page as textview like 7:00 8:00 9:00 and sooo on till 22:00 as textview
Also I have an imageview that will also increase when the text increases.
How can I achieve this?
Also I want the result text in Horizontal Scroll View with Imageview at top and text view as bottom of each imageview
char first = StartTime.charAt(0);
int StartTimeint = Integer.parseInt(String.valueOf(first));
int l;
for( l = StartTimeint; l<=22; l++){
Log.d("SeatsPage", "Time is "+l);
}
timeofseats.setText(Integer.toString(l));
This is I have done so far but I'm getting 23 as a result, the textview is not increasing
This is my XML File
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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:id="#+id/llMain"
android:layout_height="match_parent"
tools:context=".SeatsPagewithDB.SeatsPage">
<ImageView
android:id="#+id/imageView11"
android:layout_width="150px"
android:layout_height="150px"
android:layout_marginStart="28dp"
android:layout_marginEnd="326dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:srcCompat="#drawable/seat" />
<TextView
android:id="#+id/timeofseats"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="40dp"
android:layout_marginTop="12dp"
android:layout_marginEnd="334dp"
android:background="#FF0000"
android:paddingLeft="10dp"
android:paddingRight="10dp"
android:text="7:00"
android:textColor="#fff"
android:textSize="20dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/imageView11" />
</android.support.constraint.ConstraintLayout>
This is the result I am getting as layout
This what I want programmatically
The XML code that you write in your layout.xml file to create the UI is for static UI only. What you are asking is to create views dynamically during runtime. Although you can definitely create views using java code on a click of a button or something. But it is better to code less for the UI whenever possible and keep it separated from the program code. Instead use the tools given to us by the framework we are using.
In Android those tools include stuff like ListView, GridView and the newer and better RecyclerView. These views help you add other views dynamically to your UI in runtime. You define one of them or more (depending on your UI needs) once in your layout.xml and configure them using java code like any other view.
This is how you can use RecyclerView to achieve your goal. I can't explain everything how RecyclerView works and what each line of code does as it will make a very long post but I have tried to highlight main things briefly.
1. Add RecyclerView in your layout file.
activity_main.xml
<?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=".MainActivity">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:layout_marginTop="8dp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
2. Create another layout file and define the template UI of the item that the RecyclerView is going to display. RecyclerView will populate each item that it holds with this layout.
item_view.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
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="wrap_content"
android:layout_height="wrap_content"
android:gravity="center"
android:orientation="vertical">
<ImageView
android:id="#+id/imageView_alarm"
android:layout_width="90dp"
android:layout_height="90dp"
android:src="#drawable/alarm" />
<TextView
android:id="#+id/textView_Time"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="8dp"
android:background="#FF0000"
android:paddingLeft="8dp"
android:paddingRight="8dp"
android:text="Time"
android:textColor="#android:color/background_light"
android:textSize="24sp" />
</LinearLayout>
3. Create a ViewHolder class that extends from RecyclerView.ViewHolder. View holder is a RecyclerView related concept. In short it works as a wrapper around the view of a single item and aids in binding new data to the view of the item. Create a bind() function inside view holder to make your life easier.
EDIT: I have updated the class by implementing the View.OnClickListener interface, modified the constructor to pass in the context from onCreateViewHolder() and adding a setItemPosition() just for the sake to pass the item position number from onBindViewHolder() all over to here so we can use this position number in our onClick() method of the interface
MyViewHolder.java [UPDATED]
public class MyViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
private TextView textView;
private int itemPosition;
private Context mContext;
public MyViewHolder(#NonNull View itemView, Context context) {
super(itemView);
itemView.setOnClickListener(this);
mContext = context;
textView = itemView.findViewById(R.id.textView_Time);
}
void bind(String timeText)
{
textView.setText(timeText);
}
void setItemPosition(int position)
{
itemPosition = position;
}
#Override
public void onClick(View v) {
Toast.makeText(mContext, "You clicked item number: " + itemPosition , Toast.LENGTH_SHORT).show();
}
}
4. Create an Adapter class that extends from RecyclerView.Adapter. Adapter works as a bridge between the UI data and RecyclerView itself. An Adapter tells the RecyclerView what layout file to inflate and how many to inflate. RecyclerView job is to deal with how to inflate it on the UI.
EDIT : Just changed myViewHolder in onCreateViewHolder() to match the modified constructor of MyViewHolder. Added the call to setItemPosition() in the onBindViewHolder().
MyAdapter.java [UPDATED]
public class MyAdapter extends RecyclerView.Adapter {
List<String> timeIntervalList = new ArrayList<>();
#NonNull
#Override
public RecyclerView.ViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_view, parent, false);
MyViewHolder myViewHolder = new MyViewHolder(view , parent.getContext());
return myViewHolder;
}
#Override
public void onBindViewHolder(#NonNull RecyclerView.ViewHolder holder, int position) {
MyViewHolder viewHolder = (MyViewHolder) holder;
viewHolder.setItemPosition(position);
viewHolder.bind(timeIntervalList.get(position));
}
#Override
public int getItemCount() {
return timeIntervalList.size();
}
public void addItem (String timeText)
{
timeIntervalList.add(timeText);
notifyItemInserted(getItemCount());
}
}
In this adapter you will see two functions. OnCreateViewHolder() inflates the view using the template layout file for a single item and OnBindViewHolder() binds new data to the default values of the of the view just created. The data used for binding is stored in a list inside this Adapter called the timeIntervalList. This list will hold your time interval strings so they can be updated on the view.
5. Finally, use this RecyclerView where you want to use it. Like in your MainActivity.java. RecyclerView needs to be told in what fashion to display the items (e.g list , grid etc ) using a LayoutManager. LinearLayoutManager will display items either vertically or horizontally. You can see I am using your logic to increment time from string and adding new views to RecyclerView using the addItem() function of the MyAdapter class.
MainActivity.java
public class MainActivity extends AppCompatActivity {
private RecyclerView myRecyclerView;
private MyAdapter myAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
myRecyclerView = findViewById(R.id.recyclerView);
myAdapter = new MyAdapter();
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this , LinearLayoutManager.HORIZONTAL, false);
myRecyclerView.setLayoutManager(linearLayoutManager);
myRecyclerView.setAdapter(myAdapter);
// This is how you will populate the recycler view
String START_TIME = "7:00";
String END_TIME = "22:00";
char first = START_TIME.charAt(0);
int StartTimeint = Integer.parseInt(String.valueOf(first));
int l;
for( l = StartTimeint; l<=22; l++){
// This is where new item are added to recyclerView.
myAdapter.addItem(l + ":00");
}
}
}
This is the final result.
Change your activity layout XML code as follows,
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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:id="#+id/llMain"
android:layout_height="match_parent"
tools:context=".SeatsPagewithDB.SeatsPage">
<HorizontalScrollView
android:layout_width="match_parent"
android:layout_height="wrap_content"
...
...>
<LinearLayout
android:id="#+id/container"
android:orientation="horizontal"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</HorizontalScrollView>
</android.support.constraint.ConstraintLayout>
Move the textview and imageview to another XML file let's call it item_view.xml (you can name it whatever you wish). we are doing so because the root view of this file will be reused.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="wrap_content"
android:layout_height="wrap_content">
<ImageView
android:id="#+id/imageView11"
android:layout_width="150px"
android:layout_height="150px"
app:srcCompat="#drawable/seat"/>
<TextView
android:id="#+id/timeofseats"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#FF0000"
android:paddingLeft="10dp"
android:paddingRight="10dp"
android:text="7:00"
android:textColor="#fff"
android:textSize="20dp"/>
</LinearLayout>
Now make following changes in your Java file
LinearLayout container = findViewById(R.id.container); // or rootView.findViewById() for custom View and Fragment
char first = StartTime.charAt(0);
int StartTimeint = Integer.parseInt(String.valueOf(first));
for(int l = StartTimeint; l<=22; l++){
Log.d("SeatsPage", "Time is "+l);
View view = LayoutInflater.from(container.getContext()).inflate(R.layout.item_view, null);
TextView timeofseats = view.findViewById(R.id.timeofseats);
timeofseats.setText(Integer.toString(l));
container.addView(view);
}
I have an activity with a recyclerview and a button. In my recyclerview adapter in my onBindViewHolder, I set an onClickListener to the layout of the list item. When this is clicked, I want to pass the Contact (list item type) that was selected to my activity and then into a list so that it can be sent as a request to my server.
When the item is clicked, I want the colour to change to a highlighted blue colour, and for the button at the bottom of the screen to say "Continue - x contacts" (x = however many contacts are selected.) I had this working until I added the button to the activity.
The problem I'm having, is that the button isn't associating with the button ID, and it is crashing out after an item click because setText() cannot be called on a null object reference.
Error:
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setText(java.lang.CharSequence)' on a null object reference
I don't understand why the button is null, unless it is the way that I'm calling my activity object from the adapter.
Appreciate any help or advice!
RecyclerViewAdapter: (I have the other methods and ViewHolder class in the adapter and they are working fine. This is the only method that is effecting the result afaik)
private CreateGroupAccountStage2 createGroupAccountStage2 = new CreateGroupAccountStage2();
public List<Contacts> contactsList;
public List<Contacts> selectedContacts = new ArrayList<>();
#Override
public void onBindViewHolder(#NonNull final ViewHolder viewHolder, final int position) {
final Contacts contacts = contactsList.get(position);
viewHolder.contactName.setText(contacts.getContactName());
viewHolder.contactItem.setOnClickListener(new View.OnClickListener() { //Set on click listener to item layout
#Override
public void onClick(View view) {
if (!contacts.getIsPressedValue()) {
contacts.setPressedTrue(); // Method that changes boolean value stored in the Contact object
viewHolder.contactItem.setBackgroundResource(R.color.createGroupAccountContactItemPressed);
selectedContacts.add(contacts);
} else {
viewHolder.contactItem.setBackgroundResource(R.color.whiteText);
contacts.setPressedFalse(); // Method that changes boolean value stored in the Contact object
selectedContacts.remove(contacts);
}
createGroupAccountStage2.updateSelectedContacts(contactsList);
}
});
}
Activity:
Button stage2Continue;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_create_group_stage2);
stage2Continue = (Button) findViewById(R.id.createGroupAccountStage2ContinueBTN);
setUpActionBar();
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
ArrayList<Contacts> fullContactsList = new ArrayList<>();
fullContactsList.add(new Contacts(R.drawable.human_photo, "Human One", "humanone#gmail.com"));
fullContactsList.add(new Contacts(R.drawable.human_photo, "Human Two", "humantwo#gmail.com"));
setUpContactsRecyclerView(fullContactsList); //Sets up recycler view (works fine)
}
public void updateSelectedContacts(List<Contacts> contacts) {
int listSize = contacts.size();
updateContinueButton(listSize);
}
public void updateContinueButton(int selectedContactsListSize) {
String listSize = Integer.toString(selectedContactsListSize);
String buttonText = "Continue - " + listSize + " contacts";
if(selectedContactsListSize > 0) {
stage2Continue.setText(buttonText);
} else {
stage2Continue.setVisibility(View.INVISIBLE);
}
}
Layout 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:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="grouppay.dylankilbride.com.activities.CreateGroupAccountStage2">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="#style/ToolbarTheme">
<android.support.v7.widget.Toolbar
android:id="#+id/createAccountStage2Toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="#color/whiteText"
app:popupTheme="#style/ToolbarTheme" />
</android.support.design.widget.AppBarLayout>
<Button
android:id="#+id/createGroupAccountStage2ContinueBTN"
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_margin="40dp"
android:layout_alignParentBottom="true"
android:text="#string/generic_continue"
android:textSize="15sp"
android:visibility="invisible"
android:textColor="#color/whiteText"
android:background="#drawable/generic_rounded_continue_button_bg"/>
<android.support.v7.widget.RecyclerView
android:id="#+id/createGroupAccountStage2ContactsRV"
android:layout_width="match_parent"
android:layout_marginTop="?attr/actionBarSize"
android:layout_height="match_parent">
</android.support.v7.widget.RecyclerView>
Contact List Item Layout 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:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="70dp"
android:gravity="center_vertical"
android:padding="10dp"
android:id="#+id/createGroupAccountStage2ContactLL">
<de.hdodenhof.circleimageview.CircleImageView
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/createGroupAccountStage2ContactImgTV"
android:layout_width="50dp"
android:layout_height="50dp"
android:src="#drawable/human_photo"
app:civ_border_width="1dp"
app:civ_border_color="#color/profileImageBorder"/>
<TextView
android:id="#+id/createGroupAccountStage2ContactNameTV"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:textSize="20sp"
android:fontFamily="#font/cairo"
tools:text="Human Example"
/>
</LinearLayout>
It seems you need to implement onCreateViewHolder() in your RecyclerViewAdapter so that the ViewHolder is inflated with the layout including your createGroupAccountStage2ContinueBTN button
#Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = mInflater.inflate(R.layout.your_item_layout, parent, false);
return new ViewHolder(itemView);
}
Check your import, if correct contactName view is imported in your code, there is a chance that you are using same id for another view in any other xml file and because of that wrong import you are getting null for that view as that view is not inflated.
So I have this activity, which looks like this:
<android.support.constraint.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="com.example.jonas.trainingslog1.WorkoutDataActivity">
<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<android.support.constraint.ConstraintLayout
...
</android.support.constraint.ConstraintLayout>
<android.support.v7.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_constraintTop_toBottomOf="#+id/layout">
</android.support.v7.widget.RecyclerView>
</android.support.constraint.ConstraintLayout>
As you can see, the activity has an RecyclerView which items look like this:
<android.support.constraint.ConstraintLayout 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"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_marginTop="16dp"
android:layout_marginLeft="16dp"
android:layout_marginRight="16dp">
<ListView
android:id="#+id/lst"
android:layout_width="match_parent"
android:layout_height="wrap_content">
</ListView>
<Button
android:layout_width="match_parent"
android:layout_height="30dp"
app:layout_constraintTop_toBottomOf="#+id/lst"/>
The Height of the ListView in the RecyclerView Item should only be as tall as its content, so I set it to wrap_content. The problem is, this only works as long as I have set the height of the RecyclerView Item Layout to match_parent, as soon as I change it to wrap_content the ListView shows only one item. How ever I cant leave the height of the RecyclerView Item as match_parent because then every item of the RecyclerView has a lot of unused space.
Anyone hows how to fix this problem? I dont understand this behavior of the xml files. I would really appreciate help.
Add this to you listview...set the height of the listview dynamically
public static void setListViewHeightBasedOnChildren(final ListView listView) {
listView.post(new Runnable() {
#Override
public void run() {
ListAdapter listAdapter = listView.getAdapter();
if (listAdapter == null) {
return;
}
int totalHeight = listView.getPaddingTop() + listView.getPaddingBottom();
int listWidth = listView.getMeasuredWidth();
for (int i = 0; i < listAdapter.getCount(); i++) {
View listItem = listAdapter.getView(i, null, listView);
listItem.measure(
View.MeasureSpec.makeMeasureSpec(listWidth, View.MeasureSpec.EXACTLY),
View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED));
totalHeight += listItem.getMeasuredHeight();
Log.d("listItemHeight " + listItem.getMeasuredHeight(), "********");
}
Log.d("totalHeight " + totalHeight, "********");
ViewGroup.LayoutParams params = listView.getLayoutParams();
params.height = (totalHeight + (listView.getDividerHeight() * (listAdapter.getCount() - 1)));
listView.setLayoutParams(params);
listView.requestLayout();
}
});
}
add this to your recyclerview adapter
One option is to use a vertical linear layout where you put all your content of the page. Then set the height of the views (including the recyclerview) to 0dp and add a layout weight.
Problem
I'm trying to create a ListView with selectable items. I want to be able to click on an item in the ListView and have the item change color in the list, and then go on and do something else with the data from the row.
I'm using a SimpleAdapter.
How do I make it so that when I tap on a row, it turns a different color, and then when I tap on a different row, the new row is selected and changed to a new color, and the old row changes back to normal?
Code
Here is my code so far. The DBTools class is has all of the data that I want to be displayed in my ListView organized and taken care of. The getAllReceivers() method returns an ArrayList of HashMap<String, String>s that have all of my data.
MainActivity.java:
public class MainActivity extends ListActivity {
DBTools dbTools = new DBTools(this);
ArrayList<HashMap<String, String>> receiverList;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getActionBar().hide();
setContentView(R.layout.activity_main);
receiverList = dbTools.getAllReceivers();
dbTools.close();
ListView listView = getListView();
if(receiverList.size() != 0) {
SimpleAdapter adapter = new SimpleAdapter(MainActivity.this,receiverList, R.layout.receiver_entry, new String[] {"receiverId","receiverName", "fullPath"}, new int[] {R.id.receiverId, R.id.receiverName, R.id.fullPath});
setListAdapter(adapter);
}
}
}
activity_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<TableLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TableRow
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#android:color/black" >
<TextView
android:id="#+id/titleTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center_horizontal"
android:text="My List" />
</TableRow>
<ListView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#android:color/black"
android:id="#android:id/list" />
</TableLayout>
receiver_entry.xml
<?xml version="1.0" encoding="utf-8"?>
<TableRow xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="#+id/tableRow" >
<TextView
android:id="#+id/receiverId"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:visibility="gone" />
<TextView
android:id="#+id/receiverName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Robotronics" />
<TextView
android:id="#+id/fullPath"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="123.45.678.910:8088/robtrox/find" />
</TableRow>
Solution
The solution to this problem is very simple. We need to add an OnItemClickListener to our ListView to listen for clicks and respond accordingly.
So, in the onCreate() method, once you've made sure that you set of data isn't empty, you're going to want to Override the onItemClick() method to listen for the click and change the color. You're also going to want to keep track of which item you selected for the later steps, so add public int selectionId = -1; at the top of your class. Furthermore, you'll need to let the ListAdapter know that you changed something by calling ((SimpleAdapter) getListAdapter()).notifyDataSetChanged().
if(receiverList.size() != 0) {
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int index, long id) {
view.setBackgroundColor(Color.RED);
TextView receiverIdTextView = (TextView) view.findViewById(R.id.receiverId);
selectionId = Integer.valueOf(receiverIdTextView.getText().toString());
((SimpleAdapter) getListAdapter()).notifyDataSetChanged();
}
});
SimpleAdapter adapter = getNewAdapter();
setListAdapter(adapter);
}
Great! Now we have a working system that will change the color of the row that you tap. But we're not done yet. We need to make sure that the previous selection changes back to the normal color.
For this, we are going to use override the SimpleAdapter's getView() method, which is called everytime the ListView goes to draw the items being displayed in it.
It only actually displays the items it needs to - the ones that you can see. It does not render the ones above or below your screen. So if you have 200 items in a ListView, only 5 or 6, depending on the size of your screen and the size of the items, are being rendered at a time.
To override the getView() method, go up to where you initialize the adapter and change the code to this:
SimpleAdapter adapter = new SimpleAdapter(MainActivity.this,receiverList, R.layout.receiver_entry, new String[] { "receiverId","receiverName", "fullPath"}, new int[] {R.id.receiverId, R.id.receiverName, R.id.fullPath}) {
#Override
public View getView (int position, View convertView, ViewGroup parent) {
View view = super.getView(position, convertView, parent);
TextView receiverIdTextView = (TextView) view.findViewById(R.id.receiverId);
if(receiverIdTextView.getText().toString().equals(String.valueOf(selectionId))) {
view.setBackgroundColor(Color.RED);
} else {
view.setBackgroundColor(Color.WHITE);
}
return view;
}
};
Every time one of the rows is drawn, since the getView() will get called, the ListView will check if the current view has the id of row you selected. If it doesn't, it'll change the background color to white. If it does, it'll change the background color to red.
And voila! That's it! Now you are setting the background color to red when you click on an item in the ListView.
Final Code
MainActivity.java:
public class MainActivity extends ListActivity {
DBTools dbTools = new DBTools(this);
ArrayList<HashMap<String, String>> receiverList;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getActionBar().hide();
setContentView(R.layout.activity_main);
receiverList = dbTools.getAllReceivers();
dbTools.close();
ListView listView = getListView();
if(receiverList.size() != 0) {
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int index, long id) {
view.setBackgroundColor(Color.RED);
TextView receiverIdTextView = (TextView) view.findViewById(R.id.receiverId);
selectionId = Integer.valueOf(receiverIdTextView.getText().toString());
((SimpleAdapter) getListAdapter()).notifyDataSetChanged();
}
});
SimpleAdapter adapter = new SimpleAdapter(MainActivity.this,receiverList, R.layout.receiver_entry, new String[] { "receiverId","receiverName", "fullPath"}, new int[] {R.id.receiverId, R.id.receiverName, R.id.fullPath}) {
#Override
public View getView (int position, View convertView, ViewGroup parent) {
View view = super.getView(position, convertView, parent);
TextView receiverIdTextView = (TextView) view.findViewById(R.id.receiverId);
if(receiverIdTextView.getText().toString().equals(String.valueOf(selectionId))) {
view.setBackgroundColor(Color.RED);
} else {
view.setBackgroundColor(Color.WHITE);
}
return view;
}
};
setListAdapter(adapter);
}
}
}
activity_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<TableLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TableRow
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#android:color/black" >
<TextView
android:id="#+id/titleTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center_horizontal"
android:text="My List" />
</TableRow>
<ListView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#android:color/black"
android:id="#android:id/list" />
</TableLayout>
receiver_entry.xml
<?xml version="1.0" encoding="utf-8"?>
<TableRow xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="#+id/tableRow" >
<TextView
android:id="#+id/receiverId"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:visibility="gone" />
<TextView
android:id="#+id/receiverName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Robotronics" />
<TextView
android:id="#+id/fullPath"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="123.45.678.910:8088/robtrox/find" />
</TableRow>
I'm trying to make scrollable RelativeLayout, that contains some custom Views. This is the plan of cinema hall, i have x, y coordinates of places and it's width and height (that are just rectangales, actually). I just put it into this RelativeLayout:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_height="fill_parent"
android:layout_width="fill_parent"
android:padding="10px">
<ScrollView
android:layout_height="wrap_content"
android:layout_width="fill_parent">
<RelativeLayout android:id="#+id/scrollable_places"
android:layout_height="wrap_content"
android:layout_width="wrap_content">
</RelativeLayout>
</ScrollView>
I put it like this:
RelativeLayout layout = (RelativeLayout) context.findViewById(R.id.scrollable_places);
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(place.getWidth(),
place.getHeight());
params.leftMargin = place.getX();
params.topMargin = place.getY();
layout.addView(new Seat(context, place), params);
Seat class looks like this:
public class Seat extends View {
private Place place;
private boolean isRed = false;
public Seat(Context context, Place place) {
super(context);
this.place = place;
setOnClickListener(new OnSeatClickListener());
}
#Override
protected void onDraw(Canvas canvas) {
if (!isRed)
canvas.drawColor(Color.GREEN);
else
canvas.drawColor(Color.RED);
}
protected void setRed() {
isRed = true;
}
private class OnSeatClickListener implements OnClickListener {
#Override
public void onClick(View view) {
((Seat) view).setRed();
view.invalidate();
}
}
}
Views are drawing perfectly. But I have ann array of views, and when some of them go out of the screen, scrollView didn't work, there is no scroll on the screen. Have you any ideas how can I make this layout scroll?
You should try following xml file. It will work on all the devices.
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:fillViewport="true"
android:padding="10px"
android:layout_height="fill_parent"
android:layout_width="fill_parent">
<RelativeLayout android:id="#+id/scrollable_places"
android:layout_height="wrap_content"
android:layout_width="wrap_content">
</RelativeLayout>
</ScrollView>
Thanks.
In scroll view you have written android:layout_height="wrap_content" instead of using wrap_content five specific height size eg android:layout_height="100dip"
Thanks
Deepak