Added options for camera analysis intervals

Author: Redth

Details.md

@@ -2,6 +2,13 @@ ZXing.Net.Mobile is a C#/.NET library based on the open source Barcode Library:
 
 GitHub Project: https://github.com/Redth/ZXing.Net.Mobile
 
+### Changes
+ - v1.3.3
+   - Fixed Android not scanning some barcodes in Portrait
+   - Fixed Android scanning very slowly
+   - Added to MobileBarcodeScanningOptions: IntervalBetweenAnalyzingFrames to configure how 'fast' frames from the live scanner view are analyzed in an attempt to decode barcodes 
+
+
 ### Usage
 ```csharp
 buttonScan.Click += (sender, e) => {

src/ZXing.Net.Mobile/Mono/MobileBarcodeScanningOptions.cs

@@ -10,7 +10,8 @@ public class MobileBarcodeScanningOptions
 		public MobileBarcodeScanningOptions ()
 		{
 			this.PossibleFormats = new List<BarcodeFormat>();
-
+			this.DelayBetweenAnalyzingFrames = 150;
+			this.InitialDelayBeforeAnalyzingFrames = 300;
 		}
 
 		public List<BarcodeFormat> PossibleFormats { get;set; }
@@ -19,6 +20,9 @@ public MobileBarcodeScanningOptions ()
 		public bool? AutoRotate { get;set; }
 		public string CharacterSet { get;set; }
 
+		public int DelayBetweenAnalyzingFrames { get;set;}
+		public int InitialDelayBeforeAnalyzingFrames { get;set; }
+
 		public static MobileBarcodeScanningOptions Default
 		{
 			get { return new MobileBarcodeScanningOptions(); }

src/ZXing.Net.Mobile/MonoForAndroid/ZxingActivity.cs

@@ -176,7 +176,7 @@ public ZxingSurfaceView (ZxingActivity activity, MobileBarcodeScanningOptions op
 			screenResolution = new Size(this.activity.WindowManager.DefaultDisplay.Width, this.activity.WindowManager.DefaultDisplay.Height);
 
 			this.options = options;
-
+			lastPreviewAnalysis = DateTime.Now.AddMilliseconds(options.InitialDelayBeforeAnalyzingFrames);
 
 			this.reader = this.options.BuildMultiFormatReader();
 
@@ -259,11 +259,11 @@ public void SurfaceDestroyed (ISurfaceHolder holder)
 			ShutdownCamera ();
 		}
 
-		DateTime lastPreviewAnalysis = DateTime.Now.AddMilliseconds(250);
+		DateTime lastPreviewAnalysis = DateTime.Now;
 
 		public void OnPreviewFrame (byte [] bytes, Android.Hardware.Camera camera)
 		{
-			if ((DateTime.Now - lastPreviewAnalysis).TotalMilliseconds < 250)
+			if ((DateTime.Now - lastPreviewAnalysis).TotalMilliseconds < options.DelayBetweenAnalyzingFrames)
 				return;
 
 			try 

src/ZXing.Net.Mobile/MonoTouch/ZxingSurfaceView.cs

@@ -450,6 +450,8 @@ private void Worker()
 			
 			if (animated) UIView.CommitAnimations();
 		}*/
+
+		bool firstTimeWorker = true;
 
 		public void StartWorker()
         {
@@ -458,9 +460,16 @@ public void StartWorker()
 			{
 				return;
 			}
+
+			var delay = TimeSpan.FromMilliseconds(_parentViewController.ScanningOptions.DelayBetweenAnalyzingFrames);
+
+			if (firstTimeWorker)
+			{
+				delay = TimeSpan.FromMilliseconds(_parentViewController.ScanningOptions.InitialDelayBeforeAnalyzingFrames);
+				firstTimeWorker = false;
+			}
 
-			
-			 WorkerTimer = NSTimer.CreateRepeatingTimer(TimeSpan.FromMilliseconds(150), delegate { 
+			 WorkerTimer = NSTimer.CreateRepeatingTimer(delay, delegate { 
 				Worker(); 
 			});
 			NSRunLoop.Current.AddTimer(WorkerTimer, NSRunLoopMode.Default);

src/ZXing.Net.Mobile/Properties/AssemblyVersionInfo.cs

@@ -12,5 +12,5 @@
 // You can specify all the values or you can default the Build and Revision Numbers 
 // by using the '*' as shown below:
 // [assembly: AssemblyVersion("1.0.*")]
-[assembly: AssemblyVersion("1.3.2.0")]
-[assembly: AssemblyFileVersion("1.3.2.0")]
+[assembly: AssemblyVersion("1.3.3.0")]
+[assembly: AssemblyFileVersion("1.3.3.0")]

src/ZXing.Net.Mobile/WindowsPhone/ScanPage.xaml.cs

@@ -101,6 +101,7 @@ protected override void OnNavigatedTo(NavigationEventArgs e)
 
             // Initialize a new instance of SimpleCameraReader with Auto-Focus mode on
             _reader = new SimpleCameraReader(Scanner, ScanningOptions);
+			_reader.ScanInterval = ScanningOptions.DelayBetweenAnalyzingFrames;
 
             OnRequestAutoFocus += () =>
             {

src/ZXing.Net.Mobile/WindowsPhone/SimpleCameraReader.cs

@@ -55,7 +55,7 @@ public double ScanInterval
 		{
 			get
 			{
-				return _scanInterval.TotalMilliseconds <= 0 ? _scanInterval.TotalMilliseconds : 250;
+				return _scanInterval.TotalMilliseconds <= 0 ? _scanInterval.TotalMilliseconds : 150;
 			}
 			set
 			{