Added initial Android implementation (with plugin.xml and JS interface)

android/ZBar.java

@@ -0,0 +1,76 @@
+package org.cloudsky.cordovaPlugins;
+
+import org.apache.cordova.CordovaInterface;
+import org.apache.cordova.CordovaPlugin;
+import org.apache.cordova.CallbackContext;
+import org.apache.cordova.PluginResult;
+import org.json.JSONArray;
+import org.json.JSONException;
+
+import android.app.Activity;
+import android.content.Intent;
+import android.content.Context;
+
+import org.cloudsky.cordovaPlugins.ZBarScannerActivity;
+
+public class ZBar extends CordovaPlugin {
+    
+    // Configuration ---------------------------------------------------
+
+    private static int SCAN_CODE = 1;
+
+
+    // State -----------------------------------------------------------
+
+    private boolean isInProgress = false;
+    private CallbackContext scanCallbackContext;
+
+
+    // Plugin API ------------------------------------------------------
+
+    @Override
+    public boolean execute (String action, JSONArray args, CallbackContext callbackContext)
+    throws JSONException
+    {
+        if(action.equals("scan")) {
+            if(isInProgress) {
+                callbackContext.error("A scan is already in progress!");
+            } else {
+                isInProgress = true;
+                scanCallbackContext = callbackContext;
+                Context appCtx = cordova.getActivity().getApplicationContext();
+                Intent scanIntent = new Intent(appCtx, ZBarScannerActivity.class);
+                cordova.startActivityForResult(this, scanIntent, SCAN_CODE);
+            }
+            return true;
+        } else {
+            return false;
+        }
+    }
+
+
+    // External results handler ----------------------------------------
+    
+    @Override
+    public void onActivityResult (int requestCode, int resultCode, Intent result)
+    {
+        if(requestCode == SCAN_CODE) {
+            switch(resultCode) {
+                case Activity.RESULT_OK:
+                    String barcodeValue = result.getStringExtra(ZBarScannerActivity.EXTRA_QRVALUE);
+                    scanCallbackContext.success(barcodeValue);
+                    break;
+                case Activity.RESULT_CANCELED:
+                    scanCallbackContext.error("cancelled");
+                    break;
+                case ZBarScannerActivity.RESULT_ERROR:
+                    scanCallbackContext.error("Scan failed due to an error");
+                    break;
+                default:
+                    scanCallbackContext.error("Unknown error");
+            }
+            isInProgress = false;
+            scanCallbackContext = null;
+        }
+    }
+}

android/ZBarScannerActivity.java

@@ -0,0 +1,295 @@
+package org.cloudsky.cordovaPlugins;
+
+import java.io.IOException;
+
+import android.app.Activity;
+import android.content.Intent;
+import android.content.res.Resources;
+import android.hardware.Camera;
+import android.hardware.Camera.PreviewCallback;
+import android.hardware.Camera.AutoFocusCallback;
+import android.os.Bundle;
+import android.os.Handler;
+import android.view.Gravity;
+import android.view.SurfaceHolder;
+import android.view.SurfaceView;
+import android.view.ViewGroup;
+import android.widget.FrameLayout;
+import android.widget.Toast;
+
+import net.sourceforge.zbar.ImageScanner;
+import net.sourceforge.zbar.Image;
+import net.sourceforge.zbar.Symbol;
+import net.sourceforge.zbar.SymbolSet;
+import net.sourceforge.zbar.Config;
+
+public class ZBarScannerActivity extends Activity
+implements SurfaceHolder.Callback {
+
+    // Config ----------------------------------------------------------
+    
+    private static int autoFocusInterval = 500; // Interval between AFcallback and next AF attempt.
+    
+    // Public Constants ------------------------------------------------
+    
+    public static final String EXTRA_QRVALUE = "qrValue";
+    public static final int RESULT_ERROR = RESULT_FIRST_USER + 1;
+    
+    // State -----------------------------------------------------------
+    
+    private Camera camera;
+    private Handler autoFocusHandler;
+    private SurfaceView scannerSurface;
+    private SurfaceHolder holder;
+    private ImageScanner scanner;
+    private int surfW, surfH;
+
+    // For retrieving R.* resources, from the actual app package
+    // (we can't use actual.application.package.R.* in our code as we
+    // don't know the applciation package name when writing this plugin).
+    private String package_name;
+    private Resources resources;
+
+    // Static initialisers (class) -------------------------------------
+    
+    static {
+        // Needed by ZBar??
+        System.loadLibrary("iconv");
+    }
+    
+    // Activity Lifecycle ----------------------------------------------
+
+    @Override
+    public void onCreate (Bundle savedInstanceState)
+    {
+        super.onCreate(savedInstanceState);
+
+        // Initiate instance variables
+        autoFocusHandler = new Handler();
+        scanner = new ImageScanner();
+        scanner.setConfig(0, Config.X_DENSITY, 3);
+        scanner.setConfig(0, Config.Y_DENSITY, 3);
+        
+        // Set content view
+        setContentView(getResourceId("layout/cszbarscanner"));
+        
+        // Create preview SurfaceView
+        scannerSurface = new SurfaceView (this) {
+            @Override
+            public void onSizeChanged (int w, int h, int oldW, int oldH) {
+                surfW = w;
+                surfH = h;
+                matchSurfaceToPreviewRatio();
+            }
+        };
+        scannerSurface.setLayoutParams(new FrameLayout.LayoutParams(
+            ViewGroup.LayoutParams.MATCH_PARENT,
+            ViewGroup.LayoutParams.MATCH_PARENT,
+            Gravity.CENTER
+        ));
+        scannerSurface.getHolder().addCallback(this);
+        
+        // Add preview SurfaceView to the screen
+        ((FrameLayout) findViewById(getResourceId("id/csZbarScannerView"))).addView(scannerSurface);
+        findViewById(getResourceId("id/csZbarScannerTitle")).bringToFront();
+        findViewById(getResourceId("id/csZbarScannerInstructions")).bringToFront();
+    }
+    
+    @Override
+    public void onResume ()
+    {
+        super.onResume();
+        
+        try {
+            camera = Camera.open();
+        } catch (Exception e){
+            die("Error: Could not open the camera.");
+            return;
+        }
+
+        tryStartPreview();
+    }
+    
+    @Override
+    public void onPause ()
+    {
+        releaseCamera();
+        super.onPause();
+    }
+    
+    @Override
+    public void onDestroy ()
+    {
+        scanner.destroy();
+        super.onDestroy();
+    }
+
+    // Event handlers --------------------------------------------------
+
+    @Override
+    public void onBackPressed ()
+    {
+        setResult(RESULT_CANCELED);
+        super.onBackPressed();
+    }
+
+    // SurfaceHolder.Callback implementation ---------------------------
+    
+    @Override
+    public void surfaceCreated (SurfaceHolder hld)
+    {
+        tryStopPreview();
+        holder = hld;
+        tryStartPreview();
+    }
+    
+    @Override
+    public void surfaceDestroyed (SurfaceHolder holder)
+    {
+        // No surface == no preview == no point being in this Activity.
+        die("The camera surface was destroyed");
+    }
+    
+    @Override
+    public void surfaceChanged (SurfaceHolder hld, int fmt, int w, int h)
+    {
+        // Sanity check - holder must have a surface...
+        if(hld.getSurface() == null) die("There is no camera surface");
+        
+        surfW = w;
+        surfH = h;
+        matchSurfaceToPreviewRatio();
+        
+        tryStopPreview();
+        holder = hld;
+        tryStartPreview();
+    }
+
+    // Continuously auto-focus -----------------------------------------
+    
+    private AutoFocusCallback autoFocusCb = new AutoFocusCallback()
+    {
+        public void onAutoFocus(boolean success, Camera camera) {
+            autoFocusHandler.postDelayed(doAutoFocus, autoFocusInterval);
+        }
+    };
+
+    private Runnable doAutoFocus = new Runnable()
+    {
+        public void run() {
+            if(camera != null) camera.autoFocus(autoFocusCb);
+        }
+    };
+    
+    // Camera callbacks ------------------------------------------------
+    
+    // Receives frames from the camera and checks for barcodes.
+    private PreviewCallback previewCb = new PreviewCallback()
+    {
+        public void onPreviewFrame(byte[] data, Camera camera) {
+            Camera.Parameters parameters = camera.getParameters();
+            Camera.Size size = parameters.getPreviewSize();
+
+            Image barcode = new Image(size.width, size.height, "Y800");
+            barcode.setData(data);
+
+            if (scanner.scanImage(barcode) != 0) {
+                String qrValue = "";
+                
+                SymbolSet syms = scanner.getResults();
+                for (Symbol sym : syms) {
+                    qrValue = sym.getData();
+                    
+                    // Return 1st found QR code value to the calling Activity.
+                    Intent result = new Intent ();
+                    result.putExtra(EXTRA_QRVALUE, qrValue);
+                    setResult(Activity.RESULT_OK, result);
+                    finish();
+                }
+                
+            }
+        }
+    };
+   
+    // Misc ------------------------------------------------------------
+    
+    // finish() due to error
+    private void die (String msg)
+    {
+        setResult(RESULT_ERROR);
+        finish();
+    }
+
+    private int getResourceId (String typeAndName)
+    {
+        if(package_name == null) package_name = getApplication().getPackageName();
+        if(resources == null) resources = getApplication().getResources();
+        return resources.getIdentifier(typeAndName, null, package_name);
+    }
+    
+    // Release the camera resources and state.
+    private void releaseCamera ()
+    {
+        if (camera != null) {
+            autoFocusHandler.removeCallbacks(doAutoFocus);
+            camera.setPreviewCallback(null);
+            camera.release();
+            camera = null;
+        }
+    }
+    
+    // Match the aspect ratio of the preview SurfaceView with the camera's preview aspect ratio,
+    // so that the displayed preview is not stretched/squashed.
+    private void matchSurfaceToPreviewRatio () {
+        if(camera == null) return;
+        if(surfW == 0 || surfH == 0) return;
+        
+        // Resize SurfaceView to match camera preview ratio (avoid stretching).
+        Camera.Parameters params = camera.getParameters();
+        Camera.Size size = params.getPreviewSize();
+        float previewRatio = (float) size.height / size.width; // swap h and w as the preview is rotated 90 degrees
+        float surfaceRatio = (float) surfW / surfH;
+        
+        if(previewRatio > surfaceRatio) {
+            scannerSurface.setLayoutParams(new FrameLayout.LayoutParams(
+                surfW,
+                Math.round((float) surfW / previewRatio),
+                Gravity.CENTER
+            ));
+        } else if(previewRatio < surfaceRatio) {
+            scannerSurface.setLayoutParams(new FrameLayout.LayoutParams(
+                Math.round((float) surfH * previewRatio),
+                surfH,
+                Gravity.CENTER
+            ));
+        }
+    }
+    
+    // Stop the camera preview safely.
+    private void tryStopPreview () {
+        // Stop camera preview before making changes.
+        try {
+            camera.stopPreview();
+        } catch (Exception e){
+          // Preview was not running. Ignore the error.
+        }
+    }
+    
+    // Start the camera preview if possible.
+    // If start is attempted but fails, exit with error message.
+    private void tryStartPreview () {
+        if(holder != null) {
+            try {
+                // 90 degrees rotation for Portrait orientation Activity.
+                camera.setDisplayOrientation(90);
+                
+                camera.setPreviewDisplay(holder);
+                camera.setPreviewCallback(previewCb);
+                camera.startPreview();
+                camera.autoFocus(autoFocusCb);
+            } catch (IOException e) {
+                die("Could not start camera preview: " + e.getMessage());
+            }
+        }
+    }
+}

android/res/layout/cszbarscanner.xml

@@ -0,0 +1,38 @@
+<?xml version="1.0" encoding="utf-8"?>
+<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/csZbarScannerView"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:background="@color/csZbarScannerBackground" >
+    
+    <TextView android:id="@+id/csZbarScannerTitle"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:layout_gravity="top|center_horizontal"
+        android:paddingTop="15dp"
+        android:paddingBottom="5dp"
+        android:paddingLeft="5dp"
+        android:paddingRight="5dp"
+        android:gravity="center"
+        android:text="@string/csZbarScannerTitle"
+        android:textColor="@color/csZbarScannerTextColor"
+        android:background="@color/csZbarScannerTextBackground"
+        android:fontFamily="sans-serif-light"
+        android:textSize="20pt" />
+
+    <TextView android:id="@+id/csZbarScannerInstructions"
+        android:layout_gravity="bottom|center_horizontal"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:paddingTop="5dp"
+        android:paddingBottom="15dp"
+        android:paddingLeft="5dp"
+        android:paddingRight="5dp"
+        android:gravity="center"
+        android:textSize="12pt"
+        android:textColor="@color/csZbarScannerTextColor"
+        android:background="@color/csZbarScannerTextBackground"
+        android:fontFamily="sans-serif-light"
+        android:text="@string/csZbarScannerInstructions" />
+
+</FrameLayout>