Package org.eclipse.swt.internal

Class DPIUtil

java.lang.Object

org.eclipse.swt.internal.DPIUtil

public class DPIUtil
extends Object

This class hold common constants and utility functions w.r.t. to SWT high DPI functionality.

The autoScaleUp(..) methods convert from API coordinates (in SWT points) to internal high DPI coordinates (in pixels) that interface with native widgets.

The autoScaleDown(..) convert from high DPI pixels to API coordinates (in SWT points).

Since:

3.105

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final record	DPIUtil.ElementAtZoom<T>	Represents an element, such as some image data, at a specific zoom level.

Constructor Summary

Constructors

Constructor	Description
DPIUtil()

Method Summary

Modifier and Type	Method	Description
static ImageData	autoScaleImageData(Device device, ImageData imageData, float scaleFactor)
static ImageData	autoScaleImageData(Device device, ImageData imageData, int imageDataZoomFactor)	Auto-scale ImageData to device zoom that are at given zoom factor.
static int	getDeviceZoom()
static int	getNativeDeviceZoom()
static float	getScalingFactor(int zoom)	Returns scaling factor from the given device zoom
static float	getScalingFactor(int targetZoom, int currentZoom)
static int	getZoomForAutoscaleProperty(int nativeDeviceZoom)
static boolean	isSmoothScalingEnabled()
static int	mapDPIToZoom(int dpi)	Compute the zoom value based on the DPI value.
static int	mapZoomToDPI(int zoom)	Compute the DPI value value based on the zoom.
static float	pixelToPoint(float size, int zoom)
static int	pixelToPoint(int size, int zoom)
static void	runWithAutoScaleValue(String autoScaleValue, Runnable runnable)
static ImageData	scaleImageData(Device device, ImageData imageData, int targetZoom, int currentZoom)	Auto-scale image with ImageData
static ImageData	scaleImageData(Device device, DPIUtil.ElementAtZoom<ImageData> elementAtZoom, int targetZoom)
static void	setDeviceZoom(int nativeDeviceZoom)
static DPIUtil.ElementAtZoom<ImageData>	validateAndGetImageDataAtZoom(ImageDataProvider provider, int zoom)	Gets ImageData that are appropriate for the specified zoom level together with the zoom level at which the image data are.
static DPIUtil.ElementAtZoom<String>	validateAndGetImagePathAtZoom(ImageFileNameProvider provider, int zoom)	Gets the image file path that are appropriate for the specified zoom level together with the zoom level at which the image data are.
static void	validateLinearScaling(ImageDataProvider provider)

Methods inherited from class java.lang.Object

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

Constructor Details

DPIUtil

public DPIUtil()

Method Details

pixelToPoint

public static int pixelToPoint(int size,
 int zoom)

pixelToPoint

public static float pixelToPoint(float size,
 int zoom)

scaleImageData

public static ImageData scaleImageData(Device device,
 ImageData imageData,
 int targetZoom,
 int currentZoom)

Auto-scale image with ImageData

scaleImageData

public static ImageData scaleImageData(Device device,
 DPIUtil.ElementAtZoom<ImageData> elementAtZoom,
 int targetZoom)

autoScaleImageData

public static ImageData autoScaleImageData(Device device,
 ImageData imageData,
 float scaleFactor)

isSmoothScalingEnabled

public static boolean isSmoothScalingEnabled()

autoScaleImageData

public static ImageData autoScaleImageData(Device device,
 ImageData imageData,
 int imageDataZoomFactor)

Auto-scale ImageData to device zoom that are at given zoom factor.

getScalingFactor

public static float getScalingFactor(int zoom)

Returns scaling factor from the given device zoom

Returns:

float scaling factor

getScalingFactor

public static float getScalingFactor(int targetZoom,
 int currentZoom)

mapDPIToZoom

public static int mapDPIToZoom(int dpi)

Compute the zoom value based on the DPI value.

Returns:

zoom

mapZoomToDPI

public static int mapZoomToDPI(int zoom)

Compute the DPI value value based on the zoom.

Returns:

DPI

validateLinearScaling

public static void validateLinearScaling(ImageDataProvider provider)

validateAndGetImageDataAtZoom

public static DPIUtil.ElementAtZoom<ImageData> validateAndGetImageDataAtZoom(ImageDataProvider provider,
 int zoom)

Gets ImageData that are appropriate for the specified zoom level together with the zoom level at which the image data are. If there is an image at the specified zoom level, it is returned. Otherwise the next larger image at 150% and 200% is returned, if existing. If none of these is found, the 100% image is returned as a fallback. If provider or fallback image is not available, an error is thrown.

validateAndGetImagePathAtZoom

public static DPIUtil.ElementAtZoom<String> validateAndGetImagePathAtZoom(ImageFileNameProvider provider,
 int zoom)

Gets the image file path that are appropriate for the specified zoom level together with the zoom level at which the image data are. If there is an image at the specified zoom level, it is returned. Otherwise the next larger image at 150% and 200% is returned, if existing. If none of these is found, the 100% image is returned as a fallback. If provider or fallback image is not available, an error is thrown.

getNativeDeviceZoom

public static int getNativeDeviceZoom()

getDeviceZoom

public static int getDeviceZoom()

setDeviceZoom

public static void setDeviceZoom(int nativeDeviceZoom)

getZoomForAutoscaleProperty

public static int getZoomForAutoscaleProperty(int nativeDeviceZoom)

runWithAutoScaleValue

public static void runWithAutoScaleValue(String autoScaleValue,
 Runnable runnable)