Emmet Dunne
Lurker
Hi Everyone,
I am studying android programming in college - using Android Studio.
The app I am trying to create captures an image using an intent - then scales the image down and loads it as a bmp into an imageview. Once in the imageview, a canvas is created and the user should be allowed to draw lines on the image.
My lines are not appearing where the user is touching on the screen... heres my code:
I presume it is something to do when the coordinates are retrieved using event.getX() and event.getY() - this seems to get the coordinates of the entire view rather then just the imageview.
Any help would be really appreciated!
I am studying android programming in college - using Android Studio.
The app I am trying to create captures an image using an intent - then scales the image down and loads it as a bmp into an imageview. Once in the imageview, a canvas is created and the user should be allowed to draw lines on the image.
My lines are not appearing where the user is touching on the screen... heres my code:
Java:
package com.example.emmetdunner.measurements;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.content.ActivityNotFoundException;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.graphics.Path;
import android.media.Image;
import android.view.MotionEvent;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.ColorDrawable;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.LayerDrawable;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.provider.Telephony;
import android.support.v4.content.FileProvider;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import java.io.File;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
public class Measurement extends Activity implements View.OnClickListener, View.OnTouchListener{
//keep track of camera capture intent
final int requestImageCapture = 1;
Uri photoURI; //the Uri for the captured image 40
ImageView mImageView;
EditText mDialogInput;
Context mContext;
File photoFile;
String mCurrentPhotoPath;
Canvas canvas;
Paint PaintLine;
Paint PaintText;
float downx = 0, downy = 0, upx = 0, upy = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_measurement);
//retrieve a reference to the UI button
Button captureBtn = (Button) findViewById(R.id.captureButton);
//handle button clicks
captureBtn.setOnClickListener(this);
mImageView = (ImageView) findViewById(R.id.imageViewer);
}
public void onClick(View v) {
Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
// Ensure that there's a camera activity to handle the intent
if (takePictureIntent.resolveActivity(getPackageManager()) != null) {
// Create the File where the photo should go
File photoFile = null;
try {
photoFile = createImageFile();
} catch (IOException ex) {
// Error occurred while creating the File
Toast errorMessage = Toast.makeText(this, "Your droid does not support capturing images!", Toast.LENGTH_SHORT);
errorMessage.show();
}
// Continue only if the File was successfully created
if (photoFile != null) {
Uri photoURI = FileProvider.getUriForFile(this, "com.example.android.fileprovider", photoFile);
takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI);
startActivityForResult(takePictureIntent, requestImageCapture);
}
}
}
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode == RESULT_OK) {
//user is returning from capturing an image using the camera
if (requestCode == requestImageCapture) {
String baseDir = Environment.getExternalStorageDirectory().getAbsolutePath();
String newString = mCurrentPhotoPath;
// Get the dimensions of the bitmap
BitmapFactory.Options bmOptions = new BitmapFactory.Options();
bmOptions.inJustDecodeBounds = true;
BitmapFactory.decodeFile(newString, bmOptions);
int photoW = bmOptions.outWidth;
int photoH = bmOptions.outHeight;
// Get the dimensions of the View
int targetW = mImageView.getWidth();
int targetH = mImageView.getHeight();
// Determine how much to scale down the image
int scaleFactor = Math.min(photoW / targetW, photoH / targetH);
// Decode the image file into a Bitmap sized to fill the View
bmOptions.inSampleSize = scaleFactor;
bmOptions.inPurgeable = true;
bmOptions.inMutable = true;
bmOptions.inJustDecodeBounds = false;
Bitmap bmp = BitmapFactory.decodeFile(newString, bmOptions); //Load with scaling
canvas = new Canvas(bmp);
PaintLine = new Paint();
PaintLine.setColor(Color.MAGENTA);
PaintLine.setStrokeWidth(6f);
PaintLine.setStyle(Paint.Style.STROKE);
PaintText = new Paint();
PaintText.setColor(Color.MAGENTA);
PaintText.setStrokeWidth(2f);
PaintText.setStyle(Paint.Style.STROKE);
mImageView.setImageBitmap(bmp);
mImageView.setOnTouchListener(this);
}
}
}
private File createImageFile() throws IOException {
// Create an image file name
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
String imageFileName = "JPEG_" + timeStamp + "_";
File storageDir = getExternalFilesDir(Environment.DIRECTORY_PICTURES);
File image = File.createTempFile(
imageFileName, /* prefix */
".jpg", /* suffix */
storageDir /* directory */
);
// Save a file: path for use with ACTION_VIEW intents
mCurrentPhotoPath = image.getAbsolutePath();
return image;
}
public boolean onTouch(View view, MotionEvent event) {
int action = event.getAction();
switch (action) {
case MotionEvent.ACTION_DOWN:
downx = event.getX();
downy = event.getY();
Toast cord = Toast.makeText(this, Double.toString(downx) + " " + Double.toString(downy), Toast.LENGTH_SHORT);
cord.show();
break;
case MotionEvent.ACTION_MOVE:
break;
case MotionEvent.ACTION_UP:
upx = event.getX();
upy = event.getY();
showDialog();
break;
case MotionEvent.ACTION_CANCEL:
break;
default:
break;
}
return true;
}
private void showDialog(){
canvas.drawLine(downx, downy, upx, upy, PaintLine);
canvas.drawText("1", (downx + upx) / 2, ((downy + 20) + (upy + 20)) / 2, PaintText);
mImageView.invalidate();
}
}I presume it is something to do when the coordinates are retrieved using event.getX() and event.getY() - this seems to get the coordinates of the entire view rather then just the imageview.
Any help would be really appreciated!
