Develop Reference

Accessing data from barcode scanner app to use in SQLite query

This is my first question here on stack overflow, so please forgive me for any oversight or formatting errors. This issue seems simple enough, but I am not able to "put the pieces together" for some reason. I am also learning java and android studio as I go, so please forgive and educate on any bad code.
I need to gather data from my barcode scanning app, submit it to a variable, and then pass that variable through my database to fetch information based on the UPC code. I am using the ZXing library for the barcode scanner, with the handleResult method to capture the initial data.
I have the data collected within the SimpleScanner activity, but I can't figure out how to use that variable in a SQlite query. Below are the main classes I am using.
Any help would be appreciated. I can query the entire database just fine, but I need to look up the rows that match the actual item I am scanning. Thanks again!
SimpleScannerActivity.java
package com.example.android.dropr;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.database.Cursor;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.widget.Toast;
import com.google.zxing.Result;
import java.util.ArrayList;
import java.util.List;
import me.dm7.barcodescanner.zxing.ZXingScannerView;
public class SimpleScannerActivity extends MainActivity implements ZXingScannerView.ResultHandler {
private ZXingScannerView mScannerView;
#Override
public void onCreate(Bundle state) {
super.onCreate(state);
mScannerView = new ZXingScannerView(this); // Programmatically initialize the scanner view
setContentView(mScannerView); // Set the scanner view as the content view
}
#Override
public void onResume() {
super.onResume();
mScannerView.setResultHandler(this); // Register ourselves as a handler for scan results.
mScannerView.startCamera(); // Start camera on resume
}
#Override
public void onPause () {
super.onPause();
mScannerView.stopCamera(); // Stop the camera on pause
}
#Override
public void handleResult(Result rawResult) {
String TAG = "Dropr";
/**
* Create Alert Dialog, so that user has time to read the information within.
*/
AlertDialog.Builder scanInfo = new AlertDialog.Builder(this);
String messageContent = "Content - " + rawResult.getText();
String messageFormat = "Format - " + rawResult.getBarcodeFormat().toString() + ".";
scanInfo.setTitle("Scan Information:");
scanInfo.setMessage(messageContent + "\n" + messageFormat);
scanInfo.setCancelable(true);
scanInfo.setPositiveButton(
"OK",
new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int id) {
dialog.cancel();
// IF you would like to resume scanning, call this method below:
// Handle the data
Handler handler = new Handler();
handler.postDelayed(new Runnable() {
#Override
public void run() {
mScannerView.resumeCameraPreview(SimpleScannerActivity.this);
}
}, 1000);
}
});
AlertDialog showInfo = scanInfo.create();
showInfo.show();
// Do something with the result here
Log.v(TAG, rawResult.getText());
Log.v(TAG, rawResult.getBarcodeFormat().toString());
}
}
DatabaseAccess.java
package com.example.android.dropr;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import java.util.ArrayList;
import java.util.List;
public class DatabaseAccess {
private SQLiteOpenHelper openHelper;
private SQLiteDatabase database;
private static DatabaseAccess instance;
private SimpleScannerActivity scannerActivity = new SimpleScannerActivity();
/**
* Private constructor to avoid object creation from outside classes.
*
* #param context
*/
protected DatabaseAccess(Context context) {
this.openHelper = new DatabaseOpenHelper(context);
}
/**
* Return a singleton instance of DatabaseAccess.
*
* #param context
* #return the instance of DatabaseAccess
*/
public static DatabaseAccess getInstance(Context context) {
if (instance == null) {
instance = new DatabaseAccess(context);
}
return instance;
}
/**
* Open the database connection
*/
public void open() {
this.database = openHelper.getWritableDatabase();
}
/**
* Close the database connection
*/
public void close() {
if (database != null) {
this.database.close();
}
}
/**
* Read all quotes from the database.
*
* #return a list of quotes
*/
public List<String> getCodes() {
List<String> list = new ArrayList<>();
Cursor cursor = database.rawQuery("SELECT name, upc14 FROM Barcodes", null);
cursor.moveToFirst();
while (!cursor.isAfterLast()) {
list.add(cursor.getString(0));
list.add(cursor.getString(1));
cursor.moveToNext();
}
cursor.close();
return list;
}
}

I finally came up with a solution, thanks to #muratgu! I created another method that creates and stores a variable for the scanned data, and passes the variable through a query.
/**
* read a single record from the database the matches the UPC-A code scanned.
* if there is no match, do nothing.
* #param rawContent
* #return a brand name based on the matching UPC-A code that was scanned.
*/
public String getInfo(String rawContent) {
String TAG = "Getinfo():";
String content = "00" + rawContent;
String brandName = "";
Cursor cursor = database.rawQuery("SELECT name, upc12 from Barcodes WHERE '" + content + "' = upc12", null);
if(cursor.getCount() > 0) {
cursor.moveToFirst();
brandName = cursor.getString(cursor.getColumnIndex("name"));
cursor.close();
} else {
Log.v(TAG, "uh oh, something went wrong in the if loop! ");
}
return brandName;
}
This method gets called in the SimpleScannerActivity.java file, where the scanned data can be passed through the variable. The method returns the name of the item, which is then placed in the dialog box. Exactly what I needed.
Thanks again, #muratgu! you gave me enough information that I could solve the problem myself. I just had to think on it for a bit!

Have at least one item selected in Android MultiSelectListPreference

I have search now for hours through the internet and have found nothing substantial so far. The thing that I want to do is a multi choice preference view, that disables the last item and reenables it, if it is not alone anymore.
I through so far about taking the super class force read the private variables in there to write my own onPrepareDialogBuilder(AlertDialog.Builder builder). Which is configuring its own OnMultiChoiceClickListener that jumps in, in the moment where has only one item left. The problem here is, that I use a bad practice force read of a private variable and that I have so far no idea how to get the checkbox item and how to disable it. But I think looking even deeper into the Android SDK will solve this problem.
At the end, if nothing works, solving the problem with doing an overwrite the OnPreferenceChangeListener to display a toast if the user has less than one item selected. But user friendliness is a high value, that needs to be earned and that often isn't easy.
Thx.
import android.content.Context;
import android.preference.MultiSelectListPreference;
import android.util.AttributeSet;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import georg.com.flironetest_01.Variables.Units;
/**
* Created by Georg on 16/03/16.
*/
public class UnitMultipleSelectorPreference extends MultiSelectListPreference {
public UnitMultipleSelectorPreference(Context context, AttributeSet attrs) {
super(context, attrs);
List<CharSequence> humanU = new ArrayList<>();
List<CharSequence> machineU = new ArrayList<>();
Units[] all = Units.values(); // Units is a enum with a rewriten to string statement.
for (Units elem : all) {
humanU.add(elem.toString());
machineU.add(elem.name());
}
setEntries(humanU.toArray(new CharSequence[humanU.size()]));
setEntryValues(machineU.toArray(new CharSequence[machineU.size()]));
Set<String> mU = new HashSet<>();
mU.add(Units.C.name());
mU.add(Units.K.name());
setDefaultValue(mU);
}
}

Okay. To answer my own question here after the motto "self is the man": I ended up with programming my own preference panel. Below is the code. If somebody likes to look over it and give some times how to make it even more stable: feel free.
But to sum up what I did: I created my own ArrayAdapter. But DialogPreference didn't allowed me to create my own multi selector. You need to change the final dialog fragment to create a working multi selector list (see here: https://stackoverflow.com/a/17907379/5759814). That is not an easy task if you work with the DialogPreferences. The reason is these few amounts of code:
/**
* Shows the dialog associated with this Preference. This is normally initiated
* automatically on clicking on the preference. Call this method if you need to
* show the dialog on some other event.
*
* #param state Optional instance state to restore on the dialog
*/
protected void showDialog(Bundle state) {
Context context = getContext();
mWhichButtonClicked = DialogInterface.BUTTON_NEGATIVE;
mBuilder = new AlertDialog.Builder(context)
.setTitle(mDialogTitle)
.setIcon(mDialogIcon)
.setPositiveButton(mPositiveButtonText, this)
.setNegativeButton(mNegativeButtonText, this);
View contentView = onCreateDialogView();
if (contentView != null) {
onBindDialogView(contentView);
mBuilder.setView(contentView);
} else {
mBuilder.setMessage(mDialogMessage);
}
onPrepareDialogBuilder(mBuilder);
getPreferenceManager().registerOnActivityDestroyListener(this);
// Create the dialog
final Dialog dialog = mDialog = mBuilder.create();
if (state != null) {
dialog.onRestoreInstanceState(state);
}
if (needInputMethod()) {
requestInputMethod(dialog);
}
dialog.setOnDismissListener(this);
dialog.show();
}
As you can see here is a method triggered to change my dialog builder with onPrepareDialogBuilder, but it doesn't seem like that there is any other function triggered afterwards, that would allow me to change the dialog directly after its creation. And the second idea of changing the onPrepareDialogBuilder so that I can init everything there, doesn't really help, because I end up with displayed dialog windows. That lead me to my decision of creating my completely own Preference class. With that decision I loose all those nice prepared functions like onRestoreInstanceState and Co, but I now have an application with a much more persistent flow, that doesn't do any stupid things when I select zero units for my thermal view.
Below the non commented code. I'm sorry, but I think its simple enough for everybody who landing here.
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.SharedPreferences;
import android.preference.Preference;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;
import android.widget.AbsListView;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import georg.com.flironetest_01.Variables.Units;
/**
* Created by Georg on 16/03/16.
*/
public class UnitMultipleSelectorPreference extends Preference implements DialogInterface.OnClickListener, Preference.OnPreferenceClickListener {
String[] human_entries = null;
String[] machine_entries = null;
public SharedPreferences prev;
public UnitMultipleSelectorPreference(Context context, AttributeSet attrs) {
super(context, attrs);
prev = getSharedPreferences();
List<String> humanU = new ArrayList<>();
List<String> machineU = new ArrayList<>();
Units[] all = Units.values();
for (Units elem : all) {
humanU.add(elem.toString());
machineU.add(elem.name());
}
human_entries = humanU.toArray(new String[humanU.size()]);
machine_entries = machineU.toArray(new String[machineU.size()]);
Set<String> mU = new HashSet<>();
mU.add(Units.C.name());
mU.add(Units.K.name());
setDefaultValue(mU);
setOnPreferenceClickListener(this);
}
boolean[] selected = new boolean[0];
protected void onPrepareDialogBuilder(AlertDialog.Builder builder) {
if (prev == null)
return;
if (human_entries == null || machine_entries == null || human_entries.length != machine_entries.length ) {
throw new IllegalStateException(
"ListPreference requires an entries array and an entryValues array which are both the same length");
}
selected = new boolean[human_entries.length];
for (int i = 0; i < human_entries.length; i++)
selected[i] = prefSet.contains(machine_entries[i]);
String[] stringObj = new String[human_entries.length];
int i = 0;
for(CharSequence ch : human_entries)
stringObj[i++] = ch.toString();
builder.setAdapter(new MyAdapter(getContext(), android.R.layout.simple_list_item_multiple_choice, stringObj), new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
}
});
AlertDialog mDialog = builder.create();
mDialog.getListView().setChoiceMode(AbsListView.CHOICE_MODE_MULTIPLE);
mDialog.getListView().setItemsCanFocus(false);
mDialog.getListView().setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// Manage selected items here
ListView mParent = (ListView)parent;
if (mParent.getCheckedItemCount() >= 1)
selected[position] = mParent.isItemChecked(position);
if (mParent.getCheckedItemCount() == 0)
mParent.setItemChecked(position, true);
}
});
mDialog.show();
i = 0;
for (boolean select : selected)
mDialog.getListView().setItemChecked(i++, select);
}
#Override
public boolean onPreferenceClick(Preference preference) {
AlertDialog.Builder mBuilder = new AlertDialog.Builder(getContext());
mBuilder.setTitle(getTitle())
.setPositiveButton(android.R.string.ok, this)
.setNegativeButton(android.R.string.cancel, this);
onPrepareDialogBuilder(mBuilder);
return true;
}
#Override
public void onClick(DialogInterface dialog, int which) {
Toast.makeText(getContext(), "W:"+which + " | " + Arrays.toString(selected), Toast.LENGTH_SHORT).show();
switch (which) {
case -1:
if (isPersistent()) {
prefSet = new HashSet<>();
for (int i = 0; i < selected.length; i++) {
if (selected[i])
prefSet.add(machine_entries[i]);
}
getEditor().putStringSet(getKey(), prefSet).apply();
Toast.makeText(getContext(), "W:"+which + " | " + getSharedPreferences().getStringSet(getKey(),null).toString(), Toast.LENGTH_SHORT).show();
}
return;
}
}
public class MyAdapter extends ArrayAdapter<String> {
public MyAdapter(Context context, int textViewResourceId, String[] objects) {
super(context, textViewResourceId, objects);
}
#Override
public boolean isEnabled(int n) {
return true;
}
}
Set<String> prefSet;
#Override
protected void onSetInitialValue(boolean restorePersistedValue, Object defaultValue) {
super.onSetInitialValue(restorePersistedValue, defaultValue);
prev = getSharedPreferences();
if(restorePersistedValue) {
prefSet = prev.getStringSet(getKey(), new HashSet<String>());
} else {
try {
prefSet = (Set<String>)defaultValue;
if(isPersistent())
getEditor().putStringSet(getKey(), prefSet);
} catch (ClassCastException e) {
Log.e("ERROR_CAST", "Error casting the default value to Set<String>.");
}
}
}
}

A really simple solution is to set a setOnPreferenceChangeListener and just return false if the new value would be empty.
All of the code is put into onCreatePreferences.
MultiSelectListPreference infoPreference = findPreference("information");
infoPreference.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
#Override
public boolean onPreferenceChange(Preference preference, Object newValue) {
if (size(newValue) == 0){
return false;
}
return true;
}
});

How to extend Activity in a Java class already extended [duplicate]

This question already has answers here:
Extending from two classes
(13 answers)
Closed 7 years ago.
I'm developing an AR Android App using Metaio. I need to show some data when a real object has been tracked. To do this I register a callback, this is the best way that I have found.
Unfortunately to use correctly getFragmentManager(), I need to import Activity properties but i can't extend the class (already extended).
I think that getContext is the right way, but I do not know how to implement it.
This is the callback register in main activity:
metaioSDK.registerCallback(new ProvaTracking());
This is the Tracking class:
package com.metaio.Example;
import android.annotation.TargetApi;
import android.os.Build;
import android.util.Log;
import com.metaio.sdk.jni.IMetaioSDKCallback;
import com.metaio.sdk.jni.TrackingValues;
import com.metaio.sdk.jni.TrackingValuesVector;
public class ProvaTracking extends IMetaioSDKCallback {
#TargetApi(Build.VERSION_CODES.HONEYCOMB)
#Override
public void onTrackingEvent(TrackingValuesVector trackingValuesVector) {
super.onTrackingEvent(trackingValuesVector);
for (int i=0; i<trackingValuesVector.size(); i++)
{
final TrackingValues v = trackingValuesVector.get(i);
if (v.isTrackingState())
{
TestFragment trendsFragment = new TestFragment();
getFragmentManager().beginTransaction().add(android.R.id.content, trendsFragment).commit();
Log.d("Alessandro", "Works!!");
}
}
}
}

Add a constructor that takes in Context (Note that you want the Activity context, not the application context)
so you would change your class to be:
public class ProvaTracking extends IMetaioSDKCallback {
private Contect mCtx;
public ProvaTracking(Context context) {
mCtx = context;
}
#TargetApi(Build.VERSION_CODES.HONEYCOMB)
#Override
public void onTrackingEvent(TrackingValuesVector trackingValuesVector) {
super.onTrackingEvent(trackingValuesVector);
for (int i=0; i<trackingValuesVector.size(); i++)
{
final TrackingValues v = trackingValuesVector.get(i);
if (v.isTrackingState())
{
TestFragment trendsFragment = new TestFragment();
if (mCtx instanceof Activity)
((Activity) mCtx).getFragmentManager().beginTransaction().add(android.R.id.content, trendsFragment).commit();
Log.d("Alessandro", "Works!!");
}
}
}
}
then call it with metaioSDK.registerCallback(new ProvaTracking(getContext()));

NullPointerException after changing class ( Code worked before )

I'm doing basic calculator for Android in Java. My calculator worked but i had all code in one class. Then i wanted to make code more readable and i created another Calculation class and i put calculation code in there. And now for some reason my app crashes. LogCat says: NullPointerException. (My app starts fine and then when i choose desirable currency to convert and when i click on ImageButton(convert) then app crashes). Here is my code:
CroToEu class:
package com.eu.calculator;
import android.app.Activity;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.widget.ImageButton;
import android.widget.TextView;
public class CroToEur extends Activity {
TextView resultView;
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.cro_to_eur);
final ImageButton convert = (ImageButton) findViewById(R.id.converButton);
convertButton(convert);
}
private void convertButton(final ImageButton convert) {
resultView = (TextView) findViewById(R.id.resultView);
convert.setOnTouchListener(new View.OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
Calculate now = new Calculate();
now.croToEu();
if(event.getAction() == MotionEvent.ACTION_DOWN) {
convert.setImageResource(R.drawable.convert_button_ontouch);
checkForEmptyEntry();
} else if (event.getAction() == MotionEvent.ACTION_UP) {
convert.setImageResource(R.drawable.convert_button);
}
return false;
}
private void checkForEmptyEntry() {
if(Calculate.HRKfield.getText() == null || "".equals(Calculate.HRKfield.getText().toString())) {
resultView.setText("You left empty field");
} else {
resultView.setText(Calculate.HRKfield.getText()+" HRK = "+Calculate.fixDecimal+" EUR");
}
}
});
}
}
And my calculation class:
package com.eu.calculator;
import java.math.BigDecimal;
import android.app.Activity;
import android.widget.EditText;
public class Calculate extends Activity {
public static EditText HRKfield; //S tem dobimo vrednost iz polja edittext
public static double EUR = 0.133;//drži vrednost
public static Double HRK; // Možnost uporabe double za parsing
public static double result; // rezultat
public static BigDecimal fixDecimal; // rezultat pretvori na decimalko
public BigDecimal croToEu() {
HRKfield = (EditText) findViewById(R.id.enterField);
try {
HRK = Double.parseDouble(HRKfield.getText().toString()); //tukaj dobimo čisto številko, ki jo uporabnik vnese v polje
result = HRK * EUR;
fixDecimal = new BigDecimal(result);
fixDecimal = fixDecimal.setScale(2, BigDecimal.ROUND_HALF_UP);
} catch (NumberFormatException e) {
}
return fixDecimal;
}
}

Don' t extend Calculate class with Activity . Remove extends Activity in Calculate class

If you are trying to just create a helper class whcih does the calculation for you then don't extend Activity on your Calculate class. Instead get your croToEu method to return a variable and call this from the other class as follows.
Calculate now = new Calculate();
BigDecimal val = now.croToEu();
Id actually have the caluclate class as follows
public abstract class Calculate {
public static final double EUR = 0.133;//drži vrednost
public static BigDecimal croToEu(double hrkValue) {
BigDecimal fixDecimal = new BigDecimal(hrkValue * EUR);
fixDecimal = fixDecimal.setScale(2, BigDecimal.ROUND_HALF_UP);
return fixDecimal;
}
}
Then in your main activity class call
BigDecimal val = Calculate.croToEu(hrkValue);

if(Calculate.HRKfield.getText() == null || "
this is wrong to get the view of other activity .........
you are in CroToEur and your acessing the HRKfield of Calculate activity which will be null
So should pass the data from CroToEur activity to Calculate activity using intent and set that in HRKfield in onCreate of CroToEur

You are missing your onCreate() method and even setContentView in Calculate.class and so it cannot find your edittext HRKfield, and so it is throwing NullpointerException

How do i handle touch events properly in android?

Scope of the project
When a user touches the Android screen with two fingers, draw a "Frame" at each touch location with a "cursor" for each frame. Each frame is a custom slider that the cursor will move up and down. All the way up will be 100%, middle will be 0% and all the way down will be -100%. This will be used to control small motors, similar to tank turning, each touch controls a separate motor (sending signals over bluetooth). After a two touch and everything is drawn, I want to be able to lift off either finger, BUT keep the cursor at what ever location it was last at, while the other finger is free to move its cursor. When the last finger is lifted off, everything "hides" and resets to 0%.
Functionality Wanted
On two finger touch, draw separate .pngs under the touch location
After the frames and cursors are drawn, keep track of where they are relative to the frame to determine the percentage.
If a finger is lifted off, keep that fingers cursor at last known location, but the other finger can move it's cursor. Also if the finger is put back down it should be able to move its cursor again.
If both fingers are lifted off of the screen, hide everything and reset percentages to 0%
Functionality Obtained
I can draw the frames and cursors on multitouch
Positions and percentages work fine
Cursors do move properly
What doesn't work
I am unsure if I should have one custom class that handles both touch event or if i should have 2 instances of the custom class each handling their own touch events (I have tried both, the only way i get any "real" functionality is with 1 custom class handling both touch events, the other way doesn't work as intended)
When I only have 1 custom class, It works great, but I have it "hide" everything if both fingers are not on the screen, and sometimes android registers that I have lifted a finger off the screen and this causes me a lot of issues when the frames hide then re appear in a different location
When I use 2 custom classes I touch each custom class would have its own touch event, and i wouldn't have to worry about multitouch if i split the classes evenly between the screen. This was not the case, still need to deal with multitouch
Can someone explain to me how android handles their touch events. from what I have done, it seems if i lay down finger 1, the finger 2, the first finger will register a "ACTION_DOWN" and the second will register a "ACTION_POINTER_2_DOWN", BUT if i life off my first finger, my second finger is "demoted" and now all of the events my second finger registers does not related to "ACTION_POINTER_2" and instead will be "ACTION_DOWN, ACTION_UP, etc". Is this correct?
TouchUI.java
package com.robota.android;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.widget.ImageView;
public class TouchUI extends ImageView {
public static final String LEFT_TOUCHUI = "com.robota.android:id/leftTouchUI";
public static final String RIGHT_TOUCHUI = "com.robota.android:id/rightTouchUI";
private String whoAmI = new String();
private MyPoints framePts = new MyPoints();
private MyPoints cursorPts = new MyPoints();
private Bitmap frame;
private Bitmap cursor;
private int frameWidth;
private int frameHeight;
private int cursorHeight;
private boolean pointerDown = false;
private int dy;
public TouchUI(final Context context, final AttributeSet as){
super(context, as);
Log.d("TouchUI", getResources().getResourceName(this.getId()));
whoAmI = new String(getResources().getResourceName(this.getId()));
if(whoAmI.equals(LEFT_TOUCHUI)){
frame = BitmapFactory.decodeResource(getResources(), R.drawable.tank_left);
}else if(whoAmI.equals(RIGHT_TOUCHUI)){
frame = BitmapFactory.decodeResource(getResources(), R.drawable.tank_right);
}
cursor = BitmapFactory.decodeResource(getResources(), R.drawable.cursor);
frameWidth = frame.getWidth();
frameHeight = frame.getHeight();
cursorHeight = cursor.getHeight();
}
public void determinePointers(int x, int y){
framePts.setOrigin(x-frameWidth/2, y-frameHeight/2);
cursorPts.setOrigin(x-frameWidth/2, y-frameHeight/2);
}
#Override
public boolean onTouchEvent(MotionEvent e){
int x = 0;
int y = 0;
Log.d("TouchUI", ">>>>> " + whoAmI);
if(e.getAction() == MotionEvent.ACTION_DOWN){
determinePointers(x,y);
pointerDown = true;
}else if(e.getAction() == MotionEvent.ACTION_UP){
pointerDown = false;
}else if(e.getAction() == MotionEvent.ACTION_MOVE){
dy = (int)e.getY()-framePts.getY();
if(dy <= 0){
dy=0;
}else if(dy+cursorHeight/2 >= frameHeight){
dy=frameHeight;
}
sendMotorSpeed(dy);
}
return true;
}
public void sendMotorSpeed(int dy){
float motor = dy;
motor-=frameHeight;
motor*=-1;
motor = (motor/frameHeight)*255;
PacketController.updateMotorSpeeds(whoAmI, (int)motor);
}
public void onDraw(Canvas canvas){
if(pointerDown){//twoDown){
canvas.drawBitmap(frame, framePts.getX(), framePts.getY(), null);
canvas.drawBitmap(cursor, cursorPts.getX(), (cursorPts.getY()+dy), null);
}
invalidate();
}
private class MyPoints{
private int x = -100;
private int y = -100;
private int deltaY = 0;;
public MyPoints(){
this.x = 0;
this.y = 0;
}
public int getX(){
return this.x;
}
public int getY(){
return this.y;
}
public void setOrigin(int x, int y){
this.x = x;
this.y = y;
}
public int getDeltaY(){
return deltaY;
}
public void setDeltaY(int newY){
deltaY = (newY-y);
Log.d("TouchUI", "DY: " + deltaY);
}
}
}
Main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/parentLayout"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical">
<LinearLayout android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.robota.android.TouchUI xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/leftTouchUI"
android:background="#0000"
android:layout_height="match_parent"
android:layout_width="wrap_content"
android:layout_weight="1">
</com.robota.android.TouchUI>
<com.robota.android.TouchUI xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/rightTouchUI"
android:background="#0000"
android:layout_height="match_parent"
android:layout_width="wrap_content"
android:layout_weight="1">
</com.robota.android.TouchUI>
</LinearLayout>
RobotController.java (Main Activity Class)
package com.robota.android;
import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.content.ActivityNotFoundException;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.Window;
import android.widget.ScrollView;
import android.widget.TextView;
import android.widget.Toast;
public class RobotController extends Activity {
// Tag used to keep track of class in the Log
private static final String TAG = "robotController_new";
// Boolean to debugging
private static final boolean D = true;
// Intent request codes
private static final int DISCONNECT_DEVICE = 1;
private static final int CONNECT_DEVICE = 2;
private static final int REQUEST_ENABLE_BT = 3;
// Handler Codes
public static final int MESSAGE_READ = 1;
public static final int MESSAGE_WRITE = 2;
// Local Bluetooth Adapter
private BluetoothAdapter bluetoothAdapter = null;
// Bluetooth Discovery and Datahandler
private BluetoothComm btComm = null;
// Debug's TextView, this is where strings will be written to display
private TextView tv;
private ScrollView sv;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
if(D) Log.d(TAG, "++ON CREATE++");
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.main);
bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if(bluetoothAdapter == null){
if(D) Log.d(TAG, "NO BLUETOOTH DEVICE");
Toast.makeText(this, "Bluetooth is not available", Toast.LENGTH_SHORT).show();
finish();
return;
}
PacketController.controller = this;
}
public void onStart(){
super.onStart();
if(D) Log.d(TAG, "++ON START++");
if(!bluetoothAdapter.isEnabled()){
Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableIntent, REQUEST_ENABLE_BT);
}else{
// Start BluetoothComm
if(btComm == null){
setupComm();
}
}
}
/**
* Creates new Bluetooth Communication
*/
private void setupComm(){
if(D) Log.d(TAG, "+++setupComm+++");
btComm = new BluetoothComm(this, handler);
}
private void connectDevice(Intent data){
if(D) Log.d(TAG, "+++connectDevice+++");
String addr = data.getExtras()
.getString(DeviceListActivity.EXTRA_DEVICE_ADDRESS);
BluetoothDevice device = bluetoothAdapter.getRemoteDevice(addr);
if(D) Log.d(TAG,"REMOTE ADDR: "+ addr);
btComm.connect(device);
}
private void disconnectDevice(){
if(D) Log.d(TAG, "---disconnectDevice---");
if(btComm.getState() == btComm.STATE_CONNECTED){
btComm.disconnect();
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu)
{
//super.onCreateOptionsMenu(menu);
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
Intent serverIntent = null;
switch(item.getItemId()){
case R.id.insecure_connect_scan:
// Launch the DeviceListActivity to see devices and do scan
serverIntent = new Intent(this, DeviceListActivity.class);
try{
startActivityForResult(serverIntent, CONNECT_DEVICE);
}catch(ActivityNotFoundException activityNotFound){
Log.e(TAG, "Could not start DeviceListActivity(Insecure)");
}
return true;
}
return false;
}
#Override
public void onActivityResult(int requestCode, int resultCode, Intent data){
switch(requestCode){
case CONNECT_DEVICE:
if(resultCode == Activity.RESULT_OK){
connectDevice(data);
}
break;
case DISCONNECT_DEVICE:
if(resultCode == Activity.RESULT_OK){
disconnectDevice();
}
break;
}
}
public Handler getHandler(){
return this.handler;
}
public BluetoothComm getBtComm(){
return this.btComm;
}
// The Handler that gets information back from the BluetoothChatService
private final Handler handler = new Handler() {
#Override
public void handleMessage(Message msg) {
if(D) Log.d(TAG, "check message");
switch (msg.what) {
case MESSAGE_READ:
if(D) Log.d(TAG, "trying to read message");
byte[] readBuf = (byte[]) msg.obj;
// construct a string from the valid bytes in the buffer
String readMessage = new String(readBuf, 0, msg.arg1);
if(D) Log.d(TAG, "bytes: " + readBuf + " arg1: " + msg.arg1 + " Message: " + readMessage);
tv.append(readMessage);
break;
case MESSAGE_WRITE:
if(D) Log.d(TAG, "trying to send message");
String sendMessage = new String(String.valueOf(msg.obj));
}
}
};
}
Any other classes not listed I didn't believe needed to be, but if they are needed please let me know.
Any help is much appreciated

You're going to need to save the pointerId's of each point and compare them to the new Id's given with each MotionEvent. It's slightly tricky to explain, so I'll point you to this ADB Post that explains it much better than I could. Long story short? Multitouch can be tricksy, but it's not as bad as it looks at first glance.