Question

所以，我试图让手机上的手电筒/手电筒闪烁或相对快速地闪烁。我已将Cordova手电筒插件添加到我的应用程序中，它似乎工作正常，但当我尝试快速切换火炬时，没有任何变化。它似乎限于500毫秒的延迟或类似的东西。我目前正在测试运行android 4.4.4的Galaxy S4 我已经安装了其他手电筒应用程序，并试图快速打开和关闭它，它工作正常，所以我知道硬件能够更快地闪烁。

我查看了插件的源代码，但我似乎无法找到任何可以覆盖或更改以解决问题的内容。也许我只是错过了它。

任何人都有任何关于如何覆盖可能存在的延迟的想法？或者，如果有人有任何其他方法来实现这一点，我也会对这些方法感兴趣。

由于

JS：

$(document).ready(function(){
  document.addEventListener("deviceready", function() {
    setInterval(function () {
      window.plugins.flashlight.toggle();
    }, 200);
  });
});

flashlight.js

function Flashlight() {
  // track flashlight state
  this._isSwitchedOn = false;
}

Flashlight.prototype = {

  available: function (callback) {
    cordova.exec(function (avail) {
      callback(avail ? true : false);
    }, null, "Flashlight", "available", []);
  },

  switchOn: function (successCallback, errorCallback) {
    this._isSwitchedOn = true;
    cordova.exec(successCallback, errorCallback, "Flashlight", "switchOn", []);
  },

  switchOff: function (successCallback, errorCallback) {
    this._isSwitchedOn = false;
    cordova.exec(successCallback, errorCallback, "Flashlight", "switchOff", []);
  },

  toggle: function (successCallback, errorCallback) {
    if (this._isSwitchedOn) {
      this.switchOff(successCallback, errorCallback);
    } else {
      this.switchOn(successCallback, errorCallback);
    }
  }
};

Flashlight.install = function () {
  if (!window.plugins) {
    window.plugins = {};
  }

  window.plugins.flashlight = new Flashlight();
  return window.plugins.flashlight;
};

cordova.addConstructor(Flashlight.install);

flashlight.java

package nl.xservices.plugins;

import android.content.pm.FeatureInfo;
import android.content.pm.PackageManager;
import android.graphics.SurfaceTexture;
import android.hardware.Camera;
import android.os.Build;
import android.util.Log;
import org.apache.cordova.CallbackContext;
import org.apache.cordova.CordovaPlugin;
import org.json.JSONArray;
import org.json.JSONException;

public class Flashlight extends CordovaPlugin {

  private static final String ACTION_AVAILABLE = "available";
  private static final String ACTION_SWITCH_ON = "switchOn";
  private static final String ACTION_SWITCH_OFF = "switchOff";

  private static Boolean capable;
  private boolean releasing;
  private Camera mCamera;

  @Override
  public boolean execute(String action, JSONArray args, CallbackContext callbackContext) throws JSONException {
    Log.d("Flashlight", "Plugin Called: " + action);
    try {
      if (action.equals(ACTION_SWITCH_ON)) {
        // When switching on immediately after checking for isAvailable,
        // the release method may still be running, so wait a bit.
        while (releasing) {
          Thread.sleep(10);
        }
        mCamera = Camera.open();
        if (Build.VERSION.SDK_INT >= 11) { // honeycomb
          // required for (at least) the Nexus 5
          mCamera.setPreviewTexture(new SurfaceTexture(0));
        }
        toggleTorch(true, callbackContext);
        return true;
      } else if (action.equals(ACTION_SWITCH_OFF)) {
        toggleTorch(false, callbackContext);
        releaseCamera();
        return true;
      } else if (action.equals(ACTION_AVAILABLE)) {
        if (capable == null) {
          mCamera = Camera.open();
          capable = isCapable();
          releaseCamera();
        }
        callbackContext.success(capable ? 1 : 0);
        return true;
      } else {
        callbackContext.error("flashlight." + action + " is not a supported function.");
        return false;
      }
    } catch (Exception e) {
      callbackContext.error(e.getMessage());
      return false;
    }
  }

  private boolean isCapable() {
    final PackageManager packageManager = this.cordova.getActivity().getPackageManager();
    for (final FeatureInfo feature : packageManager.getSystemAvailableFeatures()) {
      if (PackageManager.FEATURE_CAMERA_FLASH.equalsIgnoreCase(feature.name))     {
        return true;
      }
    }
    return false;
  }

  private void toggleTorch(boolean switchOn, CallbackContext callbackContext) {
    final Camera.Parameters mParameters = mCamera.getParameters();
    if (isCapable()) {
      mParameters.setFlashMode(switchOn ? Camera.Parameters.FLASH_MODE_TORCH : Camera.Parameters.FLASH_MODE_OFF);
      mCamera.setParameters(mParameters);
      mCamera.startPreview();
      callbackContext.success();
    } else {
      callbackContext.error("Device is not capable of using the flashlight. Please test with flashlight.available()");
    }
  }

  private void releaseCamera() {
    releasing = true;
    // we need to release the camera, so other apps can use it
    new Thread(new Runnable() {
      public void run() {
        mCamera.setPreviewCallback(null);
        mCamera.stopPreview();
        mCamera.release();
        releasing = false;
      }
    }).start();
  }
}

Answer 1

你提出的建议并不顺利，因为手电筒是Android中较为分散的方面之一，即使你没有使用Cordova，许多手机根本无法满足你的要求并且完全是原生的。

我曾经看过手机，例如，需要将近2秒的时间才能打开和关闭灯光，这将使你的效果无法实现。

更改Cordova手电筒插件的闪烁速度

1 个答案: