Java tutorial
/* Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ package com.bringcommunications.etherpay; //import net.sourceforge.zbar.android.CameraTest.CameraPreview; import android.Manifest; import android.app.Activity; import android.content.Intent; import android.content.SharedPreferences; import android.content.pm.ActivityInfo; import android.content.pm.PackageManager; import android.os.Bundle; import android.os.CountDownTimer; import android.os.Handler; import android.support.v4.app.ActivityCompat; import android.support.v4.app.NavUtils; import android.support.v4.content.ContextCompat; import android.support.v7.app.AppCompatActivity; import android.support.v7.widget.Toolbar; import android.util.Log; import android.view.Menu; import android.view.View; import android.view.View.OnClickListener; import android.view.Window; import android.widget.FrameLayout; import android.widget.Button; import android.hardware.Camera; import android.hardware.Camera.PreviewCallback; import android.hardware.Camera.AutoFocusCallback; import android.hardware.Camera.Parameters; import android.hardware.Camera.Size; import android.widget.TextView; import android.graphics.ImageFormat; import android.widget.Toast; /* Import ZBar Class files */ 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; import com.bringcommunications.etherpay.R; public class ScanActivity //extends Activity extends AppCompatActivity implements PreviewCallback { private FrameLayout overlay_frame_layout; private String target_activity; private Camera mCamera; private CameraPreview mPreview; private Handler autoFocusHandler; private ScanActivity context; TextView instructions_view; private static final int REQUEST_CODE_ASK_PERMISSIONS = 123; //Button scanButton; ImageScanner scanner; private boolean barcodeScanned = false; private boolean previewing = true; static { System.loadLibrary("iconv"); } public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); context = this; overlay_frame_layout = new FrameLayout(getApplicationContext()); setContentView(overlay_frame_layout); View activity_scan_view = getLayoutInflater().inflate(R.layout.activity_scan, overlay_frame_layout, false); setContentView(activity_scan_view); Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); //The internal implementation of the support library just checks if the Toolbar has a title (not null) at the moment the SupportActionBar is //set up. If there is, then this title will be used instead of the window title. You can then set a dummy title while you load the real title. toolbar.setTitle(""); toolbar.setBackgroundResource(R.color.color_toolbar); setSupportActionBar(toolbar); // setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT); target_activity = getIntent().getStringExtra("TARGET_ACTIVITY"); String scan_prompt = getIntent().getStringExtra("SCAN_PROMPT"); autoFocusHandler = new Handler(); //Instance barcode scanner scanner = new ImageScanner(); scanner.setConfig(0, Config.X_DENSITY, 3); scanner.setConfig(0, Config.Y_DENSITY, 3); // int subtitle_R = target_activity.equals("SendActivity") ? R.string.scan_subtitle_send : R.string.scan_subtitle_import; String subtitle = getResources().getString(subtitle_R); String app_name = getResources().getString(R.string.app_name); toolbar.setTitle(app_name); toolbar.setSubtitle(subtitle); instructions_view = (TextView) findViewById(R.id.instructions); instructions_view.setText(scan_prompt); barcodeScanned = false; } public boolean onCreateOptionsMenu(Menu menu) { //no options menu return (false); } @Override protected void onStart() { super.onStart(); do_scan_wrapper(); } public void onPause() { super.onPause(); System.out.println("ScanActivity: in onPause"); releaseCamera(); } private void do_scan_wrapper() { int has_write_permission = ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA); if (has_write_permission != PackageManager.PERMISSION_GRANTED) { ActivityCompat.requestPermissions(this, new String[] { Manifest.permission.CAMERA }, REQUEST_CODE_ASK_PERMISSIONS); return; } do_scan_guts(); } private void do_scan_guts() { mCamera = getCameraInstance(); mPreview = new CameraPreview(this, mCamera, this, autoFocusCB); FrameLayout preview = (FrameLayout) findViewById(R.id.cameraPreview); preview.addView(mPreview); mCamera.setPreviewCallback(this); mCamera.startPreview(); previewing = true; try { mCamera.autoFocus(autoFocusCB); } catch (Exception e) { System.out.println("autofocus failed: " + e.toString()); } } @Override public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) { switch (requestCode) { case REQUEST_CODE_ASK_PERMISSIONS: if (grantResults[0] == PackageManager.PERMISSION_GRANTED) do_scan_guts(); else { String msg = getResources().getString(R.string.cant_scan_cuz_no_access_msg); Toast.makeText(this, msg, Toast.LENGTH_SHORT).show(); } break; default: super.onRequestPermissionsResult(requestCode, permissions, grantResults); } } /** A safe way to get an instance of the Camera object. */ public static Camera getCameraInstance() { Camera c = null; try { c = Camera.open(); } catch (Exception e) { System.out.println(e.toString()); } return c; } private void releaseCamera() { if (mCamera != null) { previewing = false; mCamera.setPreviewCallback(null); mCamera.stopPreview(); mCamera.release(); mCamera = null; } } // Mimic continuous auto-focusing // Mimic continuous auto-focusing AutoFocusCallback autoFocusCB = new AutoFocusCallback() { public void onAutoFocus(boolean success, Camera camera) { if (previewing && mCamera != null) autoFocusHandler.postDelayed(doAutoFocus, 1000); } }; private Runnable doAutoFocus = new Runnable() { public void run() { if (previewing && mCamera != null) mCamera.autoFocus(autoFocusCB); } }; //to fullfill contract as a PreviewCallback public void onPreviewFrame(byte[] data, Camera camera) { if (!previewing || camera == null || mCamera == null) return; Camera.Parameters parameters = camera.getParameters(); Size size = parameters.getPreviewSize(); Image barcode = new Image(size.width, size.height, "Y800"); barcode.setData(data); int result = scanner.scanImage(barcode); if (result != 0) { previewing = false; mCamera.setPreviewCallback(null); mCamera.stopPreview(); String scanned_data = "no data"; SymbolSet syms = scanner.getResults(); for (Symbol sym : syms) { //scanText.setText("barcode result " + sym.getData()); scanned_data = sym.getData(); barcodeScanned = true; } switch (target_activity) { case "SendActivity": { Intent intent = new Intent(this, SendActivity.class); //many QR codes simple contain the address, (eg 0x....); but i've seen this format also: //ethereum:<address>[?value=<value>][?gas=<suggestedGas>] String to_addr = scanned_data; if (scanned_data.contains(":0x")) { int addr_idx = scanned_data.indexOf(':') + 1; int end_idx = scanned_data.indexOf('?', addr_idx); to_addr = (end_idx < 0) ? scanned_data.substring(addr_idx) : scanned_data.substring(addr_idx, end_idx); } String size_str = "0"; if (scanned_data.contains("value=")) { int size_idx = scanned_data.indexOf("value=") + "value=".length() + 1; int end_idx = scanned_data.indexOf('?', size_idx); size_str = (end_idx < 0) ? scanned_data.substring(size_idx) : scanned_data.substring(size_idx, end_idx); } intent.putExtra("TO_ADDR", to_addr); intent.putExtra("SIZE", size_str); intent.putExtra("DATA", ""); intent.putExtra("AUTO_PAY", ""); //finish scanactivity so back key doesn't bring us back here System.out.println("ScanACtivity::onPreviewFrame -- starting SendActivity"); startActivity(intent); this.finish(); break; } case "MainActivity": { String app_uri = getResources().getString(R.string.app_uri); SharedPreferences preferences = getSharedPreferences(app_uri, MODE_PRIVATE); SharedPreferences.Editor preferences_editor = preferences.edit(); preferences_editor.putString("key", scanned_data); preferences_editor.commit(); NavUtils.navigateUpFromSameTask(this); this.finish(); break; } default: { System.out.println("TARGET_ACTIVITY not set in ScanActivity"); break; } } } } }