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.
Since:
3.105

  • Field Details

    • DPI_ZOOM_100

      private static final int DPI_ZOOM_100
      See Also:

    • deviceZoom

      private static int deviceZoom

    • nativeDeviceZoom

      private static int nativeDeviceZoom

    • AUTO_SCALE_METHOD_SETTING

      private static final DPIUtil.AutoScaleMethod AUTO_SCALE_METHOD_SETTING

    • autoScaleMethod

      private static DPIUtil.AutoScaleMethod autoScaleMethod

    • autoScaleValue

      private static AutoScaleCalculation.AutoScale autoScaleValue

    • SWT_AUTOSCALE_UPDATE_ON_RUNTIME

      static final String SWT_AUTOSCALE_UPDATE_ON_RUNTIME
      System property to enable to scale the application on runtime when a DPI change is detected.
      • "force": the application is scaled on DPI changes even if an unsupported value for swt.autoScale are defined. See allowed values in AutoScaleCalculation.
      • "true": the application is scaled on DPI changes
      • "false": the application will remain in its initial scaling
      Important: This flag is only parsed and used on Win32. Setting it to true on GTK or cocoa will be ignored.
      See Also:

    • SWT_AUTOSCALE

      private static final String SWT_AUTOSCALE
      System property that controls the autoScale functionality.
      • false: deviceZoom is set to 100%
      • integer: deviceZoom depends on the current display resolution, but only uses integer multiples of 100%. The detected native zoom is generally rounded down (e.g. at 150%, will use 100%), unless close to the next integer multiple (currently at 175%, will use 200%).
      • half: deviceZoom depends on the current display resolution, but only uses integer multiples of 50%. The detected native zoom is rounded to the closest permissible value, with tie-breaker towards even.
      • quarter: deviceZoom depends on the current display resolution, but only uses integer multiples of 25%. The detected native zoom is rounded to the closest permissible value.
      • exact: deviceZoom uses the native zoom (with 1% as minimal step).
      • <value>: deviceZoom uses the given integer value in percent as zoom level.
      The current default is "integer".
      See Also:

    • SWT_AUTOSCALE_METHOD

      private static final String SWT_AUTOSCALE_METHOD
      System property that controls the method for scaling images:
      • "nearest": nearest-neighbor interpolation, may look jagged
      • "smooth": smooth edges, may look blurry
      The current default is to use "smooth" on GTK when deviceZoom is an integer multiple of 100% and on Windows if monitor-specific scaling is enabled, and "nearest" otherwise..
      See Also:

  • Constructor Details

    • DPIUtil

      public DPIUtil()

  • Method Details

    • updateAutoScaleValue

      private static void updateAutoScaleValue()

    • isCustomAutoScale

      public static boolean isCustomAutoScale()

    • getEffectiveAutoScaleValue

      public static String getEffectiveAutoScaleValue()

    • isSetupCompatibleToMonitorSpecificScaling

      public static boolean isSetupCompatibleToMonitorSpecificScaling()
      Returns true only if the current setup is compatible with monitor-specific scaling. Returns false if:
      • Not running on Windows
      • The current auto-scale mode is incompatible
      The supported auto-scale modes are "quarter" and "exact" or explicit zoom values given by the value itself or "false". Every other value will be treated as "integer" and is thus not supported.

      Background information: Monitor-specific scaling on Windows only supports auto-scale modes in which all elements (font, images, control bounds etc.) are scaled equally or almost equally. The previously default mode "integer", which rounded the scale factor for everything but fonts to multiples of 100, is complex and difficult to realize with monitor-specific rescaling of UI elements. Since a uniform scale factor for everything should perspectively be used anyway, there will be no support for complex auto-scale modes for monitor-specific scaling.

    • isMonitorSpecificScalingEnforced

      private static boolean isMonitorSpecificScalingEnforced()

    • setMonitorSpecificScaling

      public static void setMonitorSpecificScaling(boolean activate)

    • isMonitorSpecificScalingActive

      public static boolean isMonitorSpecificScalingActive()

    • pixelToPoint

      public static int pixelToPoint(int size, int zoom)

    • pixelToPoint

      public static float pixelToPoint(float size, int zoom)

    • pixelToPoint

      public static double pixelToPoint(double 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)

    • scaleImage

      private static ImageData scaleImage(Device device, ImageData imageData, DPIUtil.ImageDrawFunction drawFunction, int scaledWidth, int scaledHeight)

    • autoScaleImageData

      public static ImageData autoScaleImageData(Device device, ImageData imageData, int targetWidth, int targetHeight)

    • 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)

    • pointToPixel

      public static int pointToPixel(int size, int zoom)

    • 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.

    • getElementAtZoom

      private static <T> DPIUtil.ElementAtZoom<T> getElementAtZoom(Function<Integer,T> elementForZoomProvider, int zoom)

    • getNativeDeviceZoom

      public static int getNativeDeviceZoom()
      Returns the native zoom of the UI and its controls according to the adapted OS elements. Particularly on Windows, this is the zoom used for fonts by the OS, no matter what autoscaling of SWT might be applied on top.

      Warning: When using monitor-specific scaling on Windows, this value may not be reasonable as there is no single zoom for the application but one per shell and its monitor. In that case, this method will return the native zoom for the shell whose zoom has last been changed (via moving the shell to another monitor or changing the zoom of a monitor).

    • getDeviceZoom

      public static int getDeviceZoom()
      Returns the zoom of the UI and its controls according to SWT autoscaling settings. It is an adapted value of getNativeDeviceZoom() based on the setting of the swt.autoScale property.

      Warning: When using monitor-specific scaling on Windows, this value may not be reasonable as there is no single zoom for the application but one per shell and its monitor. In that case, this method will return the autoscaling zoom for the shell whose zoom has last been changed (via moving the shell to another monitor or changing the zoom of a monitor).

    • setDeviceZoom

      public static void setDeviceZoom(int nativeDeviceZoom)

    • shouldUseSmoothScaling

      private static boolean shouldUseSmoothScaling()

    • getZoomForAutoscaleProperty

      public static int getZoomForAutoscaleProperty(int nativeDeviceZoom)

    • runWithAutoScaleValue

      public static void runWithAutoScaleValue(String autoScaleValue, Runnable runnable)