[chronojump] Added methods for load, resize jpeg, png using Cairo

[Xavier de Blas <xaviblas src gnome org>]

commit 081eb5a4db8cedc5cae0b486517b1513153501b7
Author: Xavier de Blas <xaviblas gmail com>
Date:   Thu Feb 1 13:58:34 2018 +0100

    Added methods for load, resize jpeg, png using Cairo

 src/gui/preferences.cs |    2 +-
 src/utilMultimedia.cs  |  170 ++++++++++++++++++++++++++++++++++++++++++++++++
 src/utilVideo.cs       |   44 ------------
 3 files changed, 171 insertions(+), 45 deletions(-)
---
diff --git a/src/gui/preferences.cs b/src/gui/preferences.cs
index 64be622..b92a2a3 100644
--- a/src/gui/preferences.cs
+++ b/src/gui/preferences.cs
@@ -328,7 +328,7 @@ public class PreferencesWindow
                        PreferencesWindowBox.radio_gstreamer_1_0.Active = true;
                PreferencesWindowBox.label_test_sound_result.Text = "";
 
-               PreferencesWindowBox.createComboCamera(UtilVideo.GetVideoDevices(), 
preferences.videoDeviceNum);
+               PreferencesWindowBox.createComboCamera(UtilMultimedia.GetVideoDevices(), 
preferences.videoDeviceNum);
        
 
                string [] decs = {"1", "2", "3"};
diff --git a/src/utilMultimedia.cs b/src/utilMultimedia.cs
new file mode 100644
index 0000000..3905997
--- /dev/null
+++ b/src/utilMultimedia.cs
@@ -0,0 +1,170 @@
+/*
+ * This file is part of ChronoJump
+ *
+ * ChronoJump is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or   
+ *    (at your option) any later version.
+ *    
+ * ChronoJump is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
+ *    GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ *  Copyright (C) 2004-2017   Xavier de Blas <xaviblas gmail com> 
+ */
+
+using System;
+using System.Text; //StringBuilder
+using System.Collections; //ArrayList
+using System.Collections.Generic; //List
+using System.Diagnostics;      //for detect OS
+using System.IO;               //for detect OS
+using Cairo;
+using Gdk;
+
+//this class tries to be a space for methods that are used in different classes
+public class UtilMultimedia
+{
+       /*
+        * VIDEO
+        */
+
+       public static string [] GetVideoDevices () {
+               List<LongoMatch.Video.Utils.Device> devices = 
LongoMatch.Video.Utils.Device.ListVideoDevices();
+               string [] devicesStr = new String[devices.Count];
+               int count = 0;
+               LogB.Information("Searching video devices");
+               foreach(LongoMatch.Video.Utils.Device dev in devices) {
+                       devicesStr[count++] = dev.ID.ToString();
+                       LogB.Information(dev.ID.ToString());
+               }
+               return devicesStr;
+       }
+
+       /*
+        * IMAGES
+        */
+
+       private enum ImageTypes { UNKNOWN, PNG, JPEG }
+       private static ImageTypes getImageType(string filename)
+       {
+               if(filename.ToLower().EndsWith("jpeg") || filename.ToLower().EndsWith("jpg"))
+                       return ImageTypes.JPEG;
+               else if(filename.ToLower().EndsWith("png"))
+                       return ImageTypes.PNG;
+
+               return ImageTypes.UNKNOWN;
+       }
+
+       public static void ResizeImages()
+       {
+               string file1 = "/home/xavier/Imatges/tenerife.png";
+               string file2 = "/home/xavier/Imatges/2016-06-07-152244.jpg";
+               string file3 = "/home/xavier/Imatges/humor-desmotivaciones-ofender-lasers.jpeg";
+
+               resizeImage(file1, "/home/xavier/Imatges/prova1.png", 100, 150);
+               resizeImage(file2, "/home/xavier/Imatges/prova2.png", 200, 200);
+               resizeImage(file3, "/home/xavier/Imatges/prova3.png", 400, 350);
+       }
+       
+       private static void resizeImage(string filenameOriginal, string filenameDest, int width, int height)
+       {
+               ImageSurface imgSurface;
+               if(getImageType(filenameOriginal) == ImageTypes.PNG)
+               {
+                       imgSurface = LoadPngToCairoImageSurface(filenameOriginal);
+               }
+               else if(getImageType(filenameOriginal) == ImageTypes.JPEG)
+               {
+                       imgSurface = LoadJpegToCairoImageSurface(filenameOriginal);
+               }
+               else //(getImageType(filenameOriginal) == ImageTypes.UNKNOWN)
+               {
+                       return;
+               }
+               
+               ImageSurfaceResize(imgSurface, filenameDest, width, height);
+       }
+
+       public static ImageSurface LoadJpegToCairoImageSurface(string jpegFilename)
+       {
+               Gdk.Pixbuf pixbuf = new Pixbuf (jpegFilename); //from a file
+               return pixbufToCairoImageSurface(pixbuf);
+       }
+
+       // Thanks to: Chris Thomson
+       // https://stackoverflow.com/questions/25106063/how-do-i-draw-pixbufs-onto-a-surface-with-cairo-sharp
+       private static ImageSurface pixbufToCairoImageSurface(Pixbuf pixbuf)
+       {
+               ImageSurface imgSurface = new ImageSurface(Format.ARGB32, pixbuf.Width, pixbuf.Height);
+
+               using (Cairo.Context cr = new Cairo.Context(imgSurface)) {
+                       Gdk.CairoHelper.SetSourcePixbuf (cr, pixbuf, 0, 0);
+                       cr.Paint ();
+                       cr.Dispose ();
+               }
+
+               return imgSurface;
+       }
+
+       public static ImageSurface LoadPngToCairoImageSurface (string pngFilename)
+       {
+               Cairo.ImageSurface imgSurface = new Cairo.ImageSurface(pngFilename);
+                Context cr = new Context(imgSurface);
+                cr.SetSource(imgSurface);
+                cr.Paint();
+               cr.Dispose ();
+
+               return imgSurface;
+       }
+
+       public static void ImageSurfaceResize(ImageSurface imgSurface, string filename_dest,
+                       int width, int height)
+       {
+               Surface surfaceResized = scale_surface(
+                               imgSurface, imgSurface.Width, imgSurface.Height, width, height);
+
+               LogB.Information("ImageFileResize - " + filename_dest);
+               try {
+                       surfaceResized.WriteToPng(filename_dest);
+               } catch {
+                       LogB.Warning("Catched at ImageFileResize");
+               }
+       }
+
+        // Thanks to: Owen Taylor
+       // https://lists.freedesktop.org/archives/cairo/2006-January/006178.html
+       private static Surface scale_surface (Surface old_surface,
+                       int old_width, int old_height,
+                       int new_width, int new_height)
+       {
+               Surface new_surface = old_surface.CreateSimilar(Cairo.Content.ColorAlpha, new_width, 
new_height);
+               Context cr = new Context (new_surface);
+
+               /* Scale *before* setting the source surface (1) */
+               cr.Scale ((double)new_width / old_width, (double)new_height / old_height);
+               cr.SetSourceSurface (old_surface, 0, 0);
+
+               /* To avoid getting the edge pixels blended with 0 alpha, which would
+                * occur with the default EXTEND_NONE. Use EXTEND_PAD for 1.2 or newer (2)
+                */
+               Cairo.Pattern pattern = new SurfacePattern (old_surface);
+               pattern.Extend = Cairo.Extend.Reflect;
+
+               /* Replace the destination with the source instead of overlaying */
+               cr.Operator = Cairo.Operator.Source;
+
+               /* Do the actual drawing */
+               cr.Paint();
+
+               cr.Dispose();
+
+               return new_surface;
+       }
+
+}