isFullScreen

Category: Application Control

Namespace: web.app.isFullScreen

Description

Check if the application is currently in fullscreen mode. Returns true if fullscreen is active, false otherwise.

Syntax

const isFullscreen = await web.app.isFullScreen();

Parameters

None

Returns

Promise<boolean> - True if in fullscreen mode, false otherwise

Example

Simple example

const isFullscreen = await web.app.isFullScreen();
console.log('Fullscreen:', isFullscreen);

Practical example

async function toggleFullscreen() {
    const isFullscreen = await web.app.isFullScreen();
    
    if (isFullscreen) {
        await web.app.exitFullScreen();
    } else {
        await web.app.enterFullScreen();
    }
}

Advanced example

async function updateFullscreenButton() {
    const isFullscreen = await web.app.isFullScreen();
    const button = document.getElementById('fullscreen-btn');
    
    if (isFullscreen) {
        button.innerHTML = '<i class="fas fa-compress"></i> Exit Fullscreen';
        button.title = 'Exit fullscreen mode (ESC)';
    } else {
        button.innerHTML = '<i class="fas fa-expand"></i> Enter Fullscreen';
        button.title = 'Enter fullscreen mode (F11)';
    }
}

// Update button on click
document.getElementById('fullscreen-btn').addEventListener('click', async () => {
    await toggleFullscreen();
    await updateFullscreenButton();
});

Use Cases

• Toggle fullscreen mode intelligently
• Update UI buttons based on fullscreen state
• Show/hide fullscreen exit instructions
• Track window state for user preferences
• Conditional rendering based on fullscreen
• Keyboard shortcut handling
• Save fullscreen preference
• Display appropriate icons (expand/compress)

Error Handling

This method does not throw errors. Always returns a boolean value.

Performance Tips

• Cache the result if checking frequently
• Use to avoid unnecessary enter/exit calls
• Combine with window state management
• Update UI reactively based on state

Related Methods

• web.app.enterFullScreen() - Enter fullscreen mode
• web.app.exitFullScreen() - Exit fullscreen mode
• web.app.windowMaximize() - Maximize window
• web.app.windowRestore() - Restore window

Notes

• Returns current fullscreen state
• Useful for toggle functionality
• Check before entering/exiting fullscreen
• Helps maintain consistent UI state