UCLA Material: Using Gestures

This is the code that is used at the pre-Hackathon training session on Thursday.

The code is explained using the “Flower” type of comments (don’t use this in production, it is used by me to illustrate many points in the code).

If you do not open the attached (scroll down to the bottom of the page to get the code).

Basically, with the Mango version of the WP7 O/S gestures are easily caught in programming by the use of the GestureSample enumerations that allow you to implement the test for the type of gesture such as tap, double tap, and so forth.

If you want, you can cut and paste any of the code as necessary.

Code Snippet

1. using System;
2. using Microsoft.Xna.Framework;
3. using Microsoft.Xna.Framework.Graphics;
4. using Microsoft.Xna.Framework.Input.Touch;
5.  
6. namespace Gestures
7. {
8.     public class Game1 : Microsoft.Xna.Framework.Game
9.     {
10.         /*******************************************************************************
11.          * This space is often referred to as the "Class Level"
12.          * ****************************************************************************/
13.         GraphicsDeviceManager graphics;
14.         SpriteBatch spriteBatch;
15.         String msg = "Perform a Touch Motion";
16.         Vector2 v_postionMsg;
17.         SpriteFont WeirdoFont;
18.  
19.         /*******************************************************************************
20.          * This is the end of the "Class Level"
21.          ******************************************************************************/
22.         public Game1()
23.         {
24.             /***************************************************************************
25.              * Class Constructor area
26.              **************************************************************************/
27.             graphics = new GraphicsDeviceManager(this);
28.             Content.RootDirectory = "Content";
29.  
30.             // Frame rate is 30 fps by default for Windows Phone.
31.             TargetElapsedTime = TimeSpan.FromTicks(333333);
32.             /**************************************************************************
33.              * This is the end of the "Class Constructor"
34.              *************************************************************************/
35.         }
36.  
37.         protected override void Initialize()
38.         {
39.             /**********************************************************************************
40.              * These are the touchpanel gestures or touchie feelies
41.              *
42.              * *******************************************************************************/
43.             TouchPanel.EnabledGestures =
44.                         GestureType.Tap | GestureType.DoubleTap
45.                         | GestureType.Hold
46.                         | GestureType.HorizontalDrag | GestureType.VerticalDrag
47.                         | GestureType.FreeDrag | GestureType.DragComplete
48.                         | GestureType.Pinch | GestureType.PinchComplete
49.                         | GestureType.Flick;
50.             /**********************************************************************************
51.              * Just initializing the postion of the indication of the touch/gesture
52.              * Could have used the "Zero" and had the indication at the top of the screen
53.              * that would have looked at:
54.              * v_postionMsg.Zero
55.              *********************************************************************************/
56.             v_postionMsg.X = 10;
57.             v_postionMsg.Y = 420;
58.             /*********************************************************************************
59.              * base.Initialize(); is inserted by the default XNA Template
60.              ********************************************************************************/
61.             base.Initialize();
62.         }
63.  
64.  
65.         protected override void LoadContent()
66.         {
67.             /******************************************************************
68.              * Create a new SpriteBatch, which can be used to draw textures.
69.              * This is put in by default, normally I do not use an object class
70.              * name with the first letter lower case because it is as
71.              * descriptive as I would like. You would make the choice as a
72.              * developer.
73.              * ***************************************************************/
74.             spriteBatch = new SpriteBatch(GraphicsDevice);
75.             WeirdoFont = Content.Load<SpriteFont>("WeirdoFont");
76.             /*****************************************************************/
77.         }
78.         protected override void Update(GameTime gameTime)
79.         {
80.             /*****************************************************************
81.              * The TouchType() method call was made using the "Extract Method"
82.              * found in the refactor fly out when you right click on a one or
83.              * more selected lines of code.
84.              * **************************************************************/
85.             TouchType();
86.             /*****************************************************************
87.              * base.Update(gameTime); is a line of code entered by the default
88.              * template.
89.              * **************************************************************/
90.             base.Update(gameTime);
91.             /****************************************************************/
92.         }
93.         protected override void Draw(GameTime gameTime)
94.         {
95.             /*****************************************************************
96.              * The following line GraphicsDevice.Clear(Color.CornFlowerBlue)
97.              * is entered by default, I changed the background to Color.White
98.              * **************************************************************/
99.             GraphicsDevice.Clear(Color.White);
100.             /*****************************************************************
101.              * spriteBatch.Begin(); starts the reading of the various
102.              * spriteBatch s
103.              * **************************************************************/
104.             spriteBatch.Begin();
105.             /*********************************************************************
106.              * The following spriteBatch.Drawstring uses the WeirdoFont, followed
107.              * by the related message, the vector that has the position of the
108.              * message that will tell you what the touch/gesture was and then the
109.              * color of the font.
110.              ********************************************************************/
111.             spriteBatch.DrawString(WeirdoFont, msg, v_postionMsg, Color.Black);
112.             /*********************************************************************
113.              * spriteBatch.End(); indicates the end of the drawing of the spritebatch
114.              * items, there could be more than one line
115.              * ******************************************************************/
116.             spriteBatch.End();
117.             /*********************************************************************
118.              * base.Draw(gameTime); is entered by default by the default template
119.              * ******************************************************************/
120.             base.Draw(gameTime);
121.         }
122.  
123.         /*************************************************************************
124.          * This method was originally written in the Update method and extracted
125.          * using the refactor flyout menu, "extract method"
126.          * **********************************************************************/
127.         private void TouchType()
128.         {
129.             /********************************************************************
130.              * Check to make sure that the TouchPanel can accept gestures
131.              *******************************************************************/
132.             if (TouchPanel.IsGestureAvailable)
133.             {
134.                 /********************************************************************
135.                  * GestureSample is an object that is contained in the .NET
136.                  * Framework NameSpace Microsoft.Xna.Framework.Input.Touch
137.                  * This is a helper enumeration that provides an easy way for
138.                  * software designers to test which gestures has been used
139.                  *******************************************************************/
140.                 GestureSample gesture = TouchPanel.ReadGesture();
141.                 /********************************************************************
142.                  * The switch is also called a "case" in other languages. What is
143.                  * included in the paratheses after the switch is the "test" that
144.                  * is performed by the software.
145.                  *******************************************************************/
146.                 switch (gesture.GestureType)
147.                 {
148.                     case GestureType.Hold:
149.                         msg = "Hold Touch";
150.                         break;
151.                     case GestureType.Tap:
152.                         msg = "Tap Touch";
153.                         break;
154.                     case GestureType.DoubleTap:
155.                         msg = "Tap Double Touch";
156.                         break;
157.  
158.                     case GestureType.HorizontalDrag:
159.                         msg = "Drag Hort Touch";
160.                         break;
161.  
162.                     case GestureType.VerticalDrag:
163.                         msg = "Drag Vert Touch";
164.                         break;
165.  
166.                     case GestureType.FreeDrag:
167.                         msg = "Free Drag Touch";
168.                         break;
169.  
170.                     case GestureType.DragComplete:
171.                         msg = "Completed Drag Touch";
172.                         break;
173.  
174.                     case GestureType.Flick:
175.                         msg = "Flick Touch";
176.                         break;
177.  
178.                     case GestureType.Pinch:
179.                         msg = "Pinch Touch";
180.                         break;
181.  
182.                     case GestureType.PinchComplete:
183.                         msg = "Pinch Done Touch";
184.                         break;
185.                     /******************************************************/
186.                 }
187.                 /************************************************
188.                  * This is how to detect the gesture position
189.                  * v_postionMsg = gesture.Position;
190.                  * and you would place the code here.
191.                  ***********************************************/
192.             }
193.         }
194.     }
195. }

TouchieFeelie.zip