0
# Application Setup
1

2
The libGDX GWT backend provides core application initialization and lifecycle management for web deployment. The main entry point is `GwtApplication`, which must be extended to create a web-deployable libGDX application.
3

4
## Core Application Classes
5

6
### GwtApplication { .api }
7

8
```java
9
public abstract class GwtApplication implements EntryPoint, Application {
10
    // Abstract methods that must be implemented
11
    public abstract GwtApplicationConfiguration getConfig();
12
    public abstract ApplicationListener createApplicationListener();
13
    
14
    // Lifecycle methods
15
    public void onModuleLoad();
16
    
17
    // Core subsystem access
18
    public Graphics getGraphics();
19
    public Audio getAudio();
20
    public Input getInput();
21
    public Files getFiles();
22
    public Net getNet();
23
    
24
    // Logging
25
    public void log(String tag, String message);
26
    public void error(String tag, String message);
27
    public void debug(String tag, String message);
28
    public void setLogLevel(int logLevel);
29
    public int getLogLevel();
30
    
31
    // Preferences and storage
32
    public Preferences getPreferences(String name);
33
    public Clipboard getClipboard();
34
    
35
    // Application control
36
    public void postRunnable(Runnable runnable);
37
    public void exit();
38
    public ApplicationType getType(); // Returns ApplicationType.WebGL
39
    public int getVersion();
40
    
41
    // Memory information
42
    public long getJavaHeap();
43
    public long getNativeHeap();
44
    public native double usedJSHeapSize();
45
    
46
    // Browser detection
47
    public static boolean isMobileDevice();
48
    public static AgentInfo agentInfo();
49
    
50
    // Canvas and preloader access
51
    public String getBaseUrl();
52
    public Preloader getPreloader();
53
    public CanvasElement getCanvasElement();
54
    
55
    // Loading and lifecycle listeners
56
    public LoadingListener getLoadingListener();
57
    public void setLoadingListener(LoadingListener loadingListener);
58
    public void addLifecycleListener(LifecycleListener listener);
59
    public void removeLifecycleListener(LifecycleListener listener);
60
}
61
```
62

63
### GwtApplicationConfiguration { .api }
64

65
```java
66
public class GwtApplicationConfiguration {
67
    // Canvas dimensions
68
    public final int width;
69
    public final int height;
70
    public final boolean usePhysicalPixels;
71
    
72
    // Layout and spacing
73
    public int padHorizontal = 10;
74
    public int padVertical = 10;
75
    
76
    // Audio configuration
77
    public boolean disableAudio;
78
    
79
    // Graphics settings
80
    public boolean antialiasing = false;
81
    public boolean stencil = false;
82
    public boolean alpha = false;
83
    public boolean premultipliedAlpha = false;
84
    public boolean preserveDrawingBuffer = false;
85
    public boolean useDebugGL = false;
86
    public boolean useGL30 = false;
87
    public boolean xrCompatible = false;
88
    
89
    // Display settings
90
    public OrientationLockType fullscreenOrientation;
91
    public String canvasId;
92
    public Panel rootPanel;
93
    public TextArea log;
94
    
95
    // Input settings
96
    public boolean useAccelerometer = true;
97
    public boolean useGyroscope = false;
98
    
99
    // Browser settings
100
    public boolean openURLInNewWindow = true;
101
    public boolean fetchAvailableOutputDevices = false;
102
    
103
    // Constructors
104
    public GwtApplicationConfiguration();
105
    public GwtApplicationConfiguration(boolean usePhysicalPixels);
106
    public GwtApplicationConfiguration(int width, int height);
107
    public GwtApplicationConfiguration(int width, int height, boolean usePhysicalPixels);
108
    
109
    // Methods
110
    public boolean isFixedSizeApplication();
111
}
112
```
113

114
### OrientationLockType { .api }
115

116
```java
117
public enum OrientationLockType {
118
    LANDSCAPE("landscape"),
119
    PORTRAIT("portrait"),
120
    PORTRAIT_PRIMARY("portrait-primary"),
121
    PORTRAIT_SECONDARY("portrait-secondary"),
122
    LANDSCAPE_PRIMARY("landscape-primary"),
123
    LANDSCAPE_SECONDARY("landscape-secondary");
124
    
125
    private final String name;
126
    
127
    private OrientationLockType(String name) {
128
        this.name = name;
129
    }
130
    
131
    public String getName() {
132
        return name;
133
    }
134
}
135
```
136

137
## Inner Classes and Interfaces
138

139
### AgentInfo { .api }
140

141
```java
142
public static class AgentInfo extends JavaScriptObject {
143
    public final native boolean isFirefox();
144
    public final native boolean isChrome();
145
    public final native boolean isSafari();
146
    public final native boolean isOpera();
147
    public final native boolean isIE();
148
    public final native String getUserAgent();
149
}
150
```
151

152
### LoadingListener { .api }
153

154
```java
155
public interface LoadingListener {
156
    void beforeSetup();
157
    void afterSetup();
158
}
159
```
160

161
## Usage Examples
162

163
### Basic Application Setup
164

165
```java
166
public class MyGameGwt extends GwtApplication {
167
    @Override
168
    public GwtApplicationConfiguration getConfig() {
169
        GwtApplicationConfiguration config = new GwtApplicationConfiguration(1024, 768);
170
        config.antialiasing = true;
171
        config.stencil = true;
172
        return config;
173
    }
174

175
    @Override
176
    public ApplicationListener createApplicationListener() {
177
        return new MyGame();
178
    }
179
}
180
```
181

182
### Full-Screen Application
183

184
```java
185
public class FullScreenGameGwt extends GwtApplication {
186
    @Override
187
    public GwtApplicationConfiguration getConfig() {
188
        GwtApplicationConfiguration config = new GwtApplicationConfiguration(0, 0); // Use available space
189
        config.fullscreenOrientation = OrientationLockType.LANDSCAPE;
190
        config.antialiasing = true;
191
        return config;
192
    }
193

194
    @Override
195
    public ApplicationListener createApplicationListener() {
196
        return new MyGame();
197
    }
198
}
199
```
200

201
### Application with Custom Loading
202

203
```java
204
public class CustomLoadingGameGwt extends GwtApplication {
205
    @Override
206
    public GwtApplicationConfiguration getConfig() {
207
        return new GwtApplicationConfiguration(800, 600);
208
    }
209

210
    @Override
211
    public ApplicationListener createApplicationListener() {
212
        return new MyGame();
213
    }
214
    
215
    @Override
216
    public Preloader createPreloader() {
217
        return new Preloader("assets.txt");
218
    }
219
    
220
    @Override  
221
    public LoadingListener getLoadingListener() {
222
        return new LoadingListener() {
223
            @Override
224
            public void beforeSetup() {
225
                // Custom pre-loading setup
226
            }
227
            
228
            @Override
229
            public void afterSetup() {
230
                // Custom post-loading setup
231
            }
232
        };
233
    }
234
}
235
```
236

237
### Browser Detection and Device-Specific Logic
238

239
```java
240
public class AdaptiveGameGwt extends GwtApplication {
241
    @Override
242
    public GwtApplicationConfiguration getConfig() {
243
        GwtApplicationConfiguration config;
244
        
245
        if (GwtApplication.isMobileDevice()) {
246
            config = new GwtApplicationConfiguration(0, 0); // Full screen on mobile
247
            config.fullscreenOrientation = OrientationLockType.LANDSCAPE;
248
        } else {
249
            config = new GwtApplicationConfiguration(1024, 768);
250
        }
251
        
252
        AgentInfo info = GwtApplication.agentInfo();
253
        if (info.isIE()) {
254
            config.antialiasing = false; // Disable for IE compatibility
255
        }
256
        
257
        return config;
258
    }
259

260
    @Override
261
    public ApplicationListener createApplicationListener() {
262
        return new MyGame();
263
    }
264
}
265
```