Class GraphicsEnvironment

java.lang.Object

vaadinx.awt.GraphicsEnvironment

public final class GraphicsEnvironment
extends Object

Import-swap target for GraphicsEnvironment — the browser viewport presented as a local display, so the maximize-to-screen idiom ports unchanged:

GraphicsEnvironment e = GraphicsEnvironment.getLocalGraphicsEnvironment();
frame.setMaximizedBounds(e.getMaximumWindowBounds());   // (0, 0, viewport)
frame.setExtendedState(frame.getExtendedState() | Frame.MAXIMIZED_BOTH);

isHeadless() is false. The JDK's answer on a server is true, which silently sends a migrated app down its no-display branch — skipping the UI it was about to build. A browser is a display, so this reports one, and every screen query below answers rather than throwing HeadlessException.

Like Toolkit this does not extend the abstract JDK class — it is the import-swap surface, not a platform environment — and selects per-method behaviour by the same tiers:

• Browser-backed, via the default device's configuration: getMaximumWindowBounds(), getCenterPoint(), getScreenDevices(), getDefaultScreenDevice().
• Delegated to the headless JDK environment, which computes these correctly and is authoritative for them because they describe the server's fonts — the same fonts Toolkit.getFontMetrics(Font) measures with: createGraphics(BufferedImage), getAllFonts(), getAvailableFontFamilyNames(), registerFont(Font), preferLocaleFonts(), preferProportionalFonts().

No method WARNs: every one of them has a real answer here.

Font delegation is what keeps getAvailableFontFamilyNames() consistent with what a FontMetrics measurement will actually report, which is the only sense in which font queries can be right at all when the glyphs are ultimately rendered by the browser.

Method Summary

Modifier and Type	Method	Description
Graphics2D	createGraphics(BufferedImage img)
Font[]	getAllFonts()
String[]	getAvailableFontFamilyNames()
String[]	getAvailableFontFamilyNames(Locale l)
Point	getCenterPoint()
GraphicsDevice	getDefaultScreenDevice()
static GraphicsEnvironment	getLocalGraphicsEnvironment()
Rectangle	getMaximumWindowBounds()	The area a maximized window should fill: the viewport, less any screen insets.
GraphicsDevice[]	getScreenDevices()
static boolean	isHeadless()
boolean	isHeadlessInstance()
void	preferLocaleFonts()
void	preferProportionalFonts()
boolean	registerFont(Font font)

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

getLocalGraphicsEnvironment

public static GraphicsEnvironment getLocalGraphicsEnvironment()

isHeadless

public static boolean isHeadless()

Returns:

always false; see the class doc for why the JDK's true is the wrong answer

isHeadlessInstance

public boolean isHeadlessInstance()

Returns:

always false — see isHeadless()

getScreenDevices

public GraphicsDevice[] getScreenDevices()

getDefaultScreenDevice

public GraphicsDevice getDefaultScreenDevice()

getMaximumWindowBounds

public Rectangle getMaximumWindowBounds()

The area a maximized window should fill: the viewport, less any screen insets.

getCenterPoint

public Point getCenterPoint()

createGraphics

public Graphics2D createGraphics(BufferedImage img)

getAllFonts

public Font[] getAllFonts()

getAvailableFontFamilyNames

public String[] getAvailableFontFamilyNames()

getAvailableFontFamilyNames

public String[] getAvailableFontFamilyNames(Locale l)

registerFont

public boolean registerFont(Font font)

Returns:

false if font conflicts with a family already present — the JDK's own contract, delegated rather than reimplemented

Throws:

NullPointerException - if font is null

preferLocaleFonts

public void preferLocaleFonts()

preferProportionalFonts

public void preferProportionalFonts()