Develop Reference

How to move an ImageView along X and Y axis with Sensor Accelerometer Data

I have an oversized image that I want to move up, down, left and right, using the Accelerometer values. I have created the following code that works, but the image moves in distinct steps and does not slide smoothly.
float[] matrix = new float[9];
mMatrix.getValues(matrix);
if (accelerometerValues[0] < MOVE_RIGHT_LIMIT) {
mMatrix.setTranslate(matrix[2] + 10, matrix[5] );
mSchematicDiagram.setImageMatrix(mMatrix);
Log.d("PROJECTA_SENSOR", "Moving Right");
Is it correct to use the setTranslate on ImageView matrix for this sort of use case and how would you create this smooth transition ?

i'm not sure what kind of image you want to move and why using matrix, but if you have an ImageView, you can do it by setting X and Y values in onSensorChanged method
#Override
public void onSensorChanged(SensorEvent event) {
if (event.sensor.getType() == Sensor.TYPE_ACCELEROMETER) {
x -= (int) event.values[0];
y += (int) event.values[1];
yourImageView.setY(y);
yourImageView.setX(x);
}
}
Here is my MainActivity code that works well (I just need to add borders, because currently the image can move out of the screen borders), probably it will help somebody.
import android.app.Activity;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.widget.ImageView;
public class MainActivity extends Activity implements SensorEventListener{
private SensorManager sensorManager;
private Sensor accelerometer;
private long lastUpdate;
ImageView mDrawable;
public static int x = 0;
public static int y = 0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mDrawable = (ImageView) findViewById(R.id.image);
sensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
accelerometer = sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
lastUpdate = System.currentTimeMillis();
}
#Override
protected void onResume() {
super.onResume();
sensorManager.registerListener(this, accelerometer,
SensorManager.SENSOR_DELAY_GAME);
}
#Override
protected void onPause() {
super.onPause();
sensorManager.unregisterListener(this);
}
#Override
public void onSensorChanged(SensorEvent event) {
if (event.sensor.getType() == Sensor.TYPE_ACCELEROMETER) {
x -= (int) event.values[0];
y += (int) event.values[1];
mDrawable.setY(y);
mDrawable.setX(x);
}
}
#Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {
}
}

How to make my app intent to an other screen when something happens

Well, I have an app with a ball, moving using the accelerometer sensor, now, I want it to intent me to the screen "GameOver.java" when the ball is touching the corners (top,bottom,left and right of the screen).
Here is my code :
package com.example.theball;
import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.drawable.ShapeDrawable;
import android.graphics.drawable.shapes.OvalShape;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.view.Menu;
import android.widget.ImageView;
#SuppressWarnings("deprecation") public class MainActivity extends Activity implements SensorEventListener {
private SensorManager sensorManager;
private Sensor accelerometer;
private long lastUpdate;
AnimatedView animatedView = null;
ShapeDrawable mDrawable = new ShapeDrawable();
public static int x;
public static int y;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// setContentView(R.layout.activity_main);
sensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
accelerometer = sensorManager
.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
lastUpdate = System.currentTimeMillis();
animatedView = new AnimatedView(this);
setContentView(animatedView);
}
#Override
protected void onResume() {
super.onResume();
sensorManager.registerListener(this, accelerometer,
SensorManager.SENSOR_DELAY_GAME);
}
#Override
protected void onPause() {
super.onPause();
sensorManager.unregisterListener(this);
}
#Override
public void onAccuracyChanged(Sensor arg0, int arg1) {
// TODO Auto-generated method stub
}
#Override
public void onSensorChanged(SensorEvent event) {
// TODO Auto-generated method stub
if (event.sensor.getType() == Sensor.TYPE_ACCELEROMETER) {
x -= (int) event.values[0];
y += (int) event.values[1];
}
}
public class AnimatedView extends ImageView {
static final int width = 50;
static final int height = 50;
public AnimatedView(Context context) {
super(context);
// TODO Auto-generated constructor stub
mDrawable = new ShapeDrawable(new OvalShape());
mDrawable.getPaint().setColor(0xffffAC23);
mDrawable.setBounds(x, y, x + width, y + height);
}
#Override
protected void onDraw(Canvas canvas) {
mDrawable.setBounds(x, y, x + width, y + height);
mDrawable.draw(canvas);
invalidate();
}
}
}

Assuming I understand your question correctly:
Every time the ball moves -- in your onSensorChanged(..) method -- you need to check if x == upper x bound or lower x bound and if y == upper y bound or lower y bound... If any of these conditions resolves to true that means the center of the ball is touching an edge and GameOver.java should be started:
EDIT:
// where 0 is the lower bound and 50 is the upper bound of our canvas
if(x <= 0 || x >= 50 || y <= 0 || y >= 50) {
Intent myIntent = new Intent(this, GameOver.class);
startActivity(myIntent);
}

How to get angle by which an android device rotated?

I want to make a compass app for my android phone in which an image of compass will rotate and show the direction change, I googled and found some tutorials like on codeofninja.com and javadecodegeeks.com but none of them are working on my device(I have Samsung S3 phone).
I am totally stuck in how do i get the angle of rotation and show the change of direction by rotation of an image. Please help me out.

You Can see this http://developer.android.com/reference/android/hardware/SensorEvent.html
http://www.workingfromhere.com/blog/2009/03/30/orientation-sensor-tips-in-android/
https://thenewcircle.com/s/post/43/using_the_sensors_api
and refer to https://stackoverflow.com/a/13817444/2771869....
You can get the screen orientation (for example in your onResume() Method) like this:
private static final int ORIENTATION_0 = 0;
private static final int ORIENTATION_90 = 3;
private static final int ORIENTATION_270 = 1;
Display display = ((WindowManager)
getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
int screenOrientation = display.getRotation();
switch (screenOrientation)
{
default:
case ORIENTATION_0: // Portrait
// do smth.
break;
case ORIENTATION_90: // Landscape right
// do smth.
break;
case ORIENTATION_270: // Landscape left
// do smth.
break;
}

You Need to use orientation sensors of the device this is a simple class demonstrating how it can be used :
package com.samplecompass;
import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Paint.Style;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.view.View;
public class CompassActivity extends Activity implements SensorEventListener {
Float azimut; // View to draw a compass
public class CustomDrawableView extends View {
Paint paint = new Paint();
public CustomDrawableView(Context context) {
super(context);
paint.setColor(0xff00ff00);
paint.setStyle(Style.STROKE);
paint.setStrokeWidth(2);
paint.setAntiAlias(true);
};
protected void onDraw(Canvas canvas) {
int width = getWidth();
int height = getHeight();
int centerx = width/2;
int centery = height/2;
canvas.drawLine(centerx, 0, centerx, height, paint);
canvas.drawLine(0, centery, width, centery, paint);
// Rotate the canvas with the azimut
if (azimut != null)
canvas.rotate(-azimut*360/(2*3.14159f), centerx, centery);
paint.setColor(0xff0000ff);
canvas.drawLine(centerx, -1000, centerx, +1000, paint);
canvas.drawLine(-1000, centery, 1000, centery, paint);
canvas.drawText("N", centerx+5, centery-10, paint);
canvas.drawText("S", centerx-10, centery+15, paint);
paint.setColor(0xff00ff00);
}
}
CustomDrawableView mCustomDrawableView;
private SensorManager mSensorManager;
Sensor accelerometer;
Sensor magnetometer;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mCustomDrawableView = new CustomDrawableView(this);
setContentView(mCustomDrawableView); // Register the sensor listeners
mSensorManager = (SensorManager)getSystemService(SENSOR_SERVICE);
accelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
magnetometer = mSensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD);
}
protected void onResume() {
super.onResume();
mSensorManager.registerListener(this, accelerometer, SensorManager.SENSOR_DELAY_UI);
mSensorManager.registerListener(this, magnetometer, SensorManager.SENSOR_DELAY_UI);
}
protected void onPause() {
super.onPause();
mSensorManager.unregisterListener(this);
}
public void onAccuracyChanged(Sensor sensor, int accuracy) { }
float[] mGravity;
float[] mGeomagnetic;
public void onSensorChanged(SensorEvent event) {
if (event.sensor.getType() == Sensor.TYPE_ACCELEROMETER)
mGravity = event.values;
if (event.sensor.getType() == Sensor.TYPE_MAGNETIC_FIELD)
mGeomagnetic = event.values;
if (mGravity != null && mGeomagnetic != null) {
float R[] = new float[9];
float I[] = new float[9];
boolean success = SensorManager.getRotationMatrix(R, I, mGravity, mGeomagnetic);
if (success) {
float orientation[] = new float[3];
SensorManager.getOrientation(R, orientation);
azimut = orientation[0]; // orientation contains: azimut, pitch and roll
}
}
mCustomDrawableView.invalidate();
}
}
you need this permissions to make this work :
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
Then if you want to rotate an image using the device's orientation you need to use Matrix this is a simple example :
Matrix matrix=new Matrix();
imageView.setScaleType(ScaleType.MATRIX); //required
matrix.postRotate((float) angle, pivX, pivY);
imageView.setImageMatrix(matrix);
So , use the SensorManager to get the orientation and the Matrix to turn your image . I didn't try it really but it is in this aspect , Good Luck

Move Ball around screen. Accelerometer. Bounce too

I have to do an app in Android that moves a ball around the screen. I need to move the ball with the accelerometer.
I have this code but the ball go around the border and doesn't bounce.
package com.example.test2;
import android.app.Activity;
import android.content.Context;
import android.content.pm.ActivityInfo;
import android.content.res.Configuration;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.drawable.ShapeDrawable;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.view.Display;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
public class test2 extends Activity implements SensorEventListener {
CustomDrawableView mCustomDrawableView = null;
ShapeDrawable mDrawable = new ShapeDrawable();
public float xPosition, xAcceleration, xVelocity = 0.0f;
public float yPosition, yAcceleration, yVelocity = 0.0f;
public float xmax, ymax;
private Bitmap mBitmap;
private Bitmap mWood;
private SensorManager sensorManager = null;
public float frameTime = 0.666f;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Set FullScreen & portrait
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
// Get a reference to a SensorManager
sensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
sensorManager.registerListener(this,
sensorManager.getDefaultSensor(Sensor.TYPE_ORIENTATION),
SensorManager.SENSOR_DELAY_GAME);
mCustomDrawableView = new CustomDrawableView(this);
setContentView(mCustomDrawableView);
// setContentView(R.layout.main);
// Calculate Boundry
Display display = getWindowManager().getDefaultDisplay();
xmax = (float) display.getWidth() - 50;
ymax = (float) display.getHeight() - 50;
}
// This method will update the UI on new sensor events
public void onSensorChanged(SensorEvent sensorEvent) {
{
if (sensorEvent.sensor.getType() == Sensor.TYPE_ORIENTATION) {
// Set sensor values as acceleration
yAcceleration = sensorEvent.values[1];
xAcceleration = sensorEvent.values[2];
updateBall();
}
}
}
private void updateBall() {
// Calculate new speed
xVelocity += (xAcceleration * frameTime);
yVelocity += (yAcceleration * frameTime);
// Calc distance travelled in that time
float xS = (xVelocity / 2) * frameTime;
float yS = (yVelocity / 2) * frameTime;
// Add to position negative due to sensor
// readings being opposite to what we want!
xPosition -= xS;
yPosition -= yS;
if (xPosition > xmax) {
xPosition = xmax;
} else if (xPosition < 0) {
xPosition = 0;
}
if (yPosition > ymax) {
yPosition = ymax;
} else if (yPosition < 0) {
yPosition = 0;
}
}
// I've chosen to not implement this method
public void onAccuracyChanged(Sensor arg0, int arg1) {
// TODO Auto-generated method stub
}
#Override
protected void onResume() {
super.onResume();
sensorManager.registerListener(this,
sensorManager.getDefaultSensor(Sensor.TYPE_ORIENTATION),
SensorManager.SENSOR_DELAY_GAME);
}
#Override
protected void onStop() {
// Unregister the listener
sensorManager.unregisterListener(this);
super.onStop();
}
public class CustomDrawableView extends View {
public CustomDrawableView(Context context) {
super(context);
Bitmap ball = BitmapFactory.decodeResource(getResources(),
R.drawable.ball);
final int dstWidth = 50;
final int dstHeight = 50;
mBitmap = Bitmap
.createScaledBitmap(ball, dstWidth, dstHeight, true);
mWood = BitmapFactory.decodeResource(getResources(),
R.drawable.wood);
}
protected void onDraw(Canvas canvas) {
final Bitmap bitmap = mBitmap;
canvas.drawBitmap(mWood, 0, 0, null);
canvas.drawBitmap(bitmap, xPosition, yPosition, null);
invalidate();
}
}
#Override
public void onConfigurationChanged(Configuration newConfig) {
// TODO Auto-generated method stub
super.onConfigurationChanged(newConfig);
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
}
}
How can I solve it?
Thank you

You want to move it with the accelerometer, but you're registering an orientation sensor listener. Register for the accelerometer instead.

Is it possible to have more than one setContentView in one class?

I am trying to print the rectangle shape and the main xml aswell as I want the shape and the figures, is this possible? If not how can I print a shape from java code and my main xml both on to my emulator? Thank you
package com.example.accel;
import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.RectF;
import android.graphics.drawable.ShapeDrawable;
import android.graphics.drawable.shapes.RectShape;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;
public class AccelActivity extends Activity implements SensorEventListener
{
/** Called when the activity is first created. */
CustomDrawableView mCustomDrawableView = null;
ShapeDrawable mDrawable = new ShapeDrawable();
public static int x;
public static int y;
public static int z;
private SensorManager sensorManager = null;
TextView x1, y1, z1;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
// Get a reference to a SensorManager
sensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
mCustomDrawableView = new CustomDrawableView(this);
setContentView(mCustomDrawableView);
setContentView(R.layout.main);
}
// This method will update the UI on new sensor events
public void onSensorChanged(SensorEvent sensorEvent)
{
{
if (sensorEvent.sensor.getType() == Sensor.TYPE_ACCELEROMETER) {
TextView tvX= (TextView)findViewById(R.id.x_axis);
TextView tvY= (TextView)findViewById(R.id.y_axis);
TextView tvZ= (TextView)findViewById(R.id.z_axis);
x = (int) Math.pow(sensorEvent.values[0], 2);
y = (int) Math.pow(sensorEvent.values[1], 2);
z = (int) Math.pow(sensorEvent.values[2], 2);
}
// if (sensorEvent.sensor.getType() == Sensor.TYPE_ORIENTATION) {
// }
}
}
// I've chosen to not implement this method
public void onAccuracyChanged(Sensor arg0, int arg1)
{
// TODO Auto-generated method stub
}
#Override
protected void onResume()
{
super.onResume();
// Register this class as a listener for the accelerometer sensor
sensorManager.registerListener(this, sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER),
SensorManager.SENSOR_DELAY_FASTEST);
// ...and the orientation sensor
}
#Override
protected void onStop()
{
// Unregister the listener
sensorManager.unregisterListener(this);
super.onStop();
}
public class CustomDrawableView extends View
{
static final int width = 150;
static final int height = 250;
public CustomDrawableView(Context context)
{
super(context);
mDrawable = new ShapeDrawable(new RectShape());
mDrawable.getPaint().setColor(0xff74AC23);
mDrawable.setBounds(x, y, x + width, y + height);
}
protected void onDraw(Canvas canvas)
{
RectF rect = new RectF(AccelActivity.x, AccelActivity.y, AccelActivity.x + width, AccelActivity.y
+ height); // set bounds of rectangle
Paint p = new Paint(); // set some paint options
p.setColor(Color.BLUE);
canvas.drawRect(rect, p);
invalidate();
}
}
}

yes, you can.
setcontentview(anotherLayout), so you pring the new layout in your activity.
or you can define other elements in your mainLayout and you manipulate it by the function setVisibily
if you need elementA:
elementA = findViewById(R.id.elementA);
elementA.setVisibility(true);
and if you don't need it:
elementA.setVisibility(false);