Package panamagl.canvas.swt

Class PixelScaleSupportSWT

java.lang.Object

panamagl.canvas.swt.PixelScaleSupportSWT

public class PixelScaleSupportSWT
extends Object

HiDPI plumbing for GLCanvasSWT.

Reads the pixel scale platform by platform:

• cocoa: MacOSBackingScaleFactor.read(org.eclipse.swt.widgets.Control), because SWT's Monitor.getZoom() returns 100 on Retina;
• gtk / win32: canvas.getMonitor().getZoom() / 100.0.

Wires SWT.ZoomChanged on the display (available since SWT 4.24 / 3.122 — confirmed in 3.126.0). On macOS, additionally listens to SWT.Move on the canvas because cocoa does not fire ZoomChanged when the window is moved between Retina and non-Retina monitors.

Constructor Summary

Constructors

Constructor	Description
PixelScaleSupportSWT(org.eclipse.swt.widgets.Canvas canvas)

Method Summary

Modifier and Type	Method	Description
void	addListener(panamagl.canvas.PixelScaleListener l)
panamagl.canvas.PixelScale	current()
panamagl.canvas.PixelScale	read()	Read the current pixel scale based on the platform-specific source.
void	removeListener(panamagl.canvas.PixelScaleListener l)
void	start()	Install listeners.
void	stop()

Methods inherited from class java.lang.Object

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

Constructor Details

PixelScaleSupportSWT

public PixelScaleSupportSWT(org.eclipse.swt.widgets.Canvas canvas)

Method Details

read

public panamagl.canvas.PixelScale read()

Read the current pixel scale based on the platform-specific source.

current

public panamagl.canvas.PixelScale current()

start

public void start()

Install listeners. Idempotent. Must be called from the SWT display thread.

stop

public void stop()

addListener

public void addListener(panamagl.canvas.PixelScaleListener l)

removeListener

public void removeListener(panamagl.canvas.PixelScaleListener l)