Java tutorial
/* Copyright 2017 Salath Lab - EPFL - Boris Conforty Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. */ package com.reactlibrary; import android.support.annotation.Nullable; import android.util.Log; import com.facebook.react.bridge.Arguments; import com.facebook.react.bridge.ReadableArray; import com.facebook.react.bridge.ReadableMap; import com.facebook.react.bridge.ReadableType; import com.facebook.react.bridge.WritableArray; import com.facebook.react.bridge.WritableMap; import com.facebook.react.common.MapBuilder; import com.facebook.react.modules.core.RCTNativeAppEventEmitter; import com.facebook.react.uimanager.SimpleViewManager; import com.facebook.react.uimanager.ThemedReactContext; import com.facebook.react.uimanager.UIManagerModule; import com.facebook.react.uimanager.annotations.ReactProp; import com.facebook.react.uimanager.events.Event; import com.facebook.react.uimanager.events.EventDispatcher; import com.facebook.react.uimanager.events.RCTEventEmitter; import com.scandit.barcodepicker.BarcodePicker; import com.scandit.barcodepicker.OnScanListener; import com.scandit.barcodepicker.ScanSession; import com.scandit.barcodepicker.ScanSettings; import com.scandit.recognition.Barcode; import java.util.List; import java.util.Locale; import java.util.Map; public class SGScanditPicker extends SimpleViewManager<BarcodePicker> implements OnScanListener { private static final String REACT_CLASS = "SGScanditPicker"; private static final int COMMAND_STOP_SCANNING = 0; private static final int COMMAND_START_SCANNING = 1; private static final int COMMAND_START_SCANNING_IN_PAUSED_STATE = 2; private static final int COMMAND_PAUSE_SCANNING = 3; private static final int COMMAND_SET_SETTINGS = 4; private static final int COMMAND_GET_SETTINGS = 5; public static final String COMMAND_DONE_EVENT_NAME = "COMMAND_DONE_EVENT_NAME"; private static final Map<String, Integer> COMMAND_MAP = MapBuilder.of("stopScanning", COMMAND_STOP_SCANNING, "startScanning", COMMAND_START_SCANNING, "startScanningInPausedState", COMMAND_START_SCANNING_IN_PAUSED_STATE, "pauseScanning", COMMAND_PAUSE_SCANNING, "setSettings", COMMAND_SET_SETTINGS, "getSettings", COMMAND_GET_SETTINGS); private static final String DID_SCAN_EVENT_KEY_NAME = "SGScanditPickerDidScan"; private static final String SETTINGS_DID_CHANGE_EVENT_KEY_NAME = "SGScanditPickerSettingsDidChange"; private static final String DID_SCAN_EVENT_NAME = "onDidScan"; private static final String SETTINGS_DID_CHANGE_EVENT_NAME = "onSettingsDidChange"; private static final String NEWLY_RECOGNIZED_CODES = "newlyRecognizedCodes"; private BarcodePicker picker; private ScanSettings scanSettings = ScanSettings.create(); private EventDispatcher eventDispatcher; private RCTNativeAppEventEmitter nativeAppEventEmitter; @Override public String getName() { return REACT_CLASS; } @Override public BarcodePicker createViewInstance(ThemedReactContext context) { // Store event dispatcher for emission of events eventDispatcher = context.getNativeModule(UIManagerModule.class).getEventDispatcher(); nativeAppEventEmitter = context.getJSModule(RCTNativeAppEventEmitter.class); // BarcodePicker extends View picker = new BarcodePicker(context, scanSettings); // Tell picker to call our didScan method on scan picker.setOnScanListener(this); return picker; } @ReactProp(name = "settings") public void setSettings(BarcodePicker view, @Nullable ReadableMap settings) { /* Source code shows that the following settings are handled: recognitionMode: "code", "text" codeDuplicateFilter: simply there or not cameraFacingPreference: "back", "front" workingRange: "standard", "long" deviceName: String relativeZoom: double highDensityModeEnabled: boolean codeRejectionEnabled: boolean restrictedAreaScanningEnabled: boolean scanningHotSpot: Point activeScanningAreaLandscape: Rect areaSettingsPortrait: ScanAreaSettings areaSettingsLandscape: ScanAreaSettings activeScanningAreaPortrait: Rect textRecognition: TextRecognitionSettings enabledSymbologies is handled separately, since ScanSettings.createWithJson does not seem to process it... */ scanSettings = ScanditBarcodeHelpers.scanSettingsByMergingOldAndNew(scanSettings, settings); picker.applyScanSettings(scanSettings); emitSettings(); } // Tell React Native the commands we respond to @Override public Map<String, Integer> getCommandsMap() { return COMMAND_MAP; } private void emitSettings() { WritableMap event = ScanditBarcodeHelpers.scanSettingsToWritableMap(scanSettings); eventDispatcher.dispatchEvent(new SettingsDidChangeEvent(picker.getId(), event)); //this.deviceEventEmitterModule.emit(GET_SETTINGS_EVENT_NAME, event); } // This is called by React Native whenever a command is sent to us @Override public void receiveCommand(BarcodePicker view, int commandType, @Nullable final ReadableArray args) { int argCount = args == null ? 0 : args.size(); final WritableMap promiseResponse = Arguments.createMap(); if (argCount > 0) { if (args.getType(args.size() - 1) == ReadableType.Map) { ReadableMap map = args.getMap(args.size() - 1); if (map.hasKey("commandid")) { int commandid = map.getInt("commandid"); promiseResponse.putInt("commandid", commandid); argCount--; } } } switch (commandType) { case COMMAND_STOP_SCANNING: { picker.stopScanning(); return; } case COMMAND_START_SCANNING: { picker.startScanning(false, new Runnable() { @Override public void run() { new PromiseSender(promiseResponse) { @Override public Object getResponse() { return "Scan started"; } }; } }); return; } case COMMAND_START_SCANNING_IN_PAUSED_STATE: { picker.startScanning(true); return; } case COMMAND_PAUSE_SCANNING: { picker.pauseScanning(); return; } case COMMAND_SET_SETTINGS: { if (argCount > 0) { ReadableMap map = args.getMap(0); setSettings(null, map); new PromiseSender(promiseResponse) { @Override public Object getResponse() { return ScanditBarcodeHelpers.scanSettingsToWritableMap(scanSettings); } }; } else { final int c = argCount; new PromiseSender(promiseResponse) { @Override public Object getResponse() { promiseFailed = true; return "Cannot set null settings" + c; } }; } return; } case COMMAND_GET_SETTINGS: { new PromiseSender(promiseResponse) { @Override public Object getResponse() { return ScanditBarcodeHelpers.scanSettingsToWritableMap(scanSettings); } }; emitSettings(); return; } default: throw new IllegalArgumentException(String.format(Locale.ENGLISH, "Unsupported command %d received by %s.", commandType, getClass().getSimpleName())); } } @Nullable @Override public Map getExportedCustomDirectEventTypeConstants() { Log.d("React", "COMMANDS DONE2"); return MapBuilder.builder() .put(SETTINGS_DID_CHANGE_EVENT_KEY_NAME, MapBuilder.of("registrationName", SETTINGS_DID_CHANGE_EVENT_NAME)) .put(DID_SCAN_EVENT_KEY_NAME, MapBuilder.of("registrationName", DID_SCAN_EVENT_NAME)).build(); } // Called by picker whenever a scan occurs public void didScan(ScanSession scanSession) { List<Barcode> newBarcodes = scanSession.getNewlyRecognizedCodes(); WritableArray newlyRecognizedCodes = Arguments.createArray(); for (Barcode barcode : newBarcodes) { newlyRecognizedCodes.pushMap(ScanditBarcodeHelpers.barcodeToWritableMap(barcode)); } WritableMap event = Arguments.createMap(); event.putArray(NEWLY_RECOGNIZED_CODES, newlyRecognizedCodes); eventDispatcher.dispatchEvent(new DidScanEvent(picker.getId(), event)); } private class DidScanEvent extends NativeEvent<DidScanEvent> { public static final String EVENT_NAME = DID_SCAN_EVENT_KEY_NAME; protected DidScanEvent(int viewTag, WritableMap event) { super(viewTag, event); } @Override public String getEventName() { return EVENT_NAME; } } private class SettingsDidChangeEvent extends NativeEvent<SettingsDidChangeEvent> { public static final String EVENT_NAME = SETTINGS_DID_CHANGE_EVENT_KEY_NAME; protected SettingsDidChangeEvent(int viewTag, WritableMap event) { super(viewTag, event); } @Override public String getEventName() { return EVENT_NAME; } } private abstract class PromiseSender { public final WritableMap promiseResponse; public boolean promiseFailed = false; public PromiseSender(WritableMap promiseResponse) { this.promiseResponse = promiseResponse; if (promiseResponse.hasKey("commandid")) { addResponse(); nativeAppEventEmitter.emit(COMMAND_DONE_EVENT_NAME, promiseResponse); } } public abstract Object getResponse(); private void addResponse() { final String key = "result"; Object value = getResponse(); if (value instanceof Boolean) promiseResponse.putBoolean(key, (Boolean) value); else if (value instanceof String) promiseResponse.putString(key, (String) value); else if (value instanceof Double) promiseResponse.putDouble(key, (Double) value); else if (value instanceof Integer) promiseResponse.putInt(key, (Integer) value); else if (value instanceof WritableMap) promiseResponse.putMap(key, (WritableMap) value); else if (value instanceof WritableArray) promiseResponse.putArray(key, (WritableArray) value); else if (value == null) promiseResponse.putNull(key); if (promiseFailed) { promiseResponse.putString("type", "reject"); } else { promiseResponse.putString("type", "resolve"); } } } }