CSSTUDIO-2749 Add configuration option 'org.csstudio.display.builder.representation/svg_rendering_resolution_factor'.

Author: abrahamwolk

app/display/representation-javafx/src/main/java/org/csstudio/display/builder/representation/javafx/SVGHelper.java

@@ -21,6 +21,7 @@
 
 import javafx.scene.image.Image;
 import org.csstudio.display.builder.model.util.ModelResourceUtil;
+import org.csstudio.display.builder.representation.Preferences;
 import org.phoebus.ui.javafx.ImageCache;
 import org.phoebus.ui.javafx.svg.SVGTranscoder;
 
@@ -53,11 +54,20 @@ public class SVGHelper {
      */
     public static Image loadSVG(String imageFileName, double width, double height) {
         String cachedSVGFileName = imageFileName + "_" + width + "_" + height;
+
+        double svg_rendering_resolution_factor;
+        if (!Double.isNaN(Preferences.svg_rendering_resolution_factor) && Preferences.svg_rendering_resolution_factor > 0) {
+            svg_rendering_resolution_factor = Preferences.svg_rendering_resolution_factor;
+        }
+        else {
+            logger.log(Level.WARNING, "The option 'org.csstudio.display.builder.representation/svg_rendering_resolution_factor' is set to an invalid value. Setting svg_rendering_resolution_factor to 1.");
+            svg_rendering_resolution_factor = 1.0;
+        }
         return ImageCache.cache(cachedSVGFileName, () ->
         {
             // Open the image from the stream created from the resource file.
             try (InputStream inputStream = ModelResourceUtil.openResourceStream(imageFileName)) {
-                return SVGTranscoder.loadSVG(inputStream, width, height);
+                return SVGTranscoder.loadSVG(inputStream, width*svg_rendering_resolution_factor, height*svg_rendering_resolution_factor);
             } catch (Exception ex) {
                 logger.log(Level.WARNING, String.format("Failure loading image: %s", imageFileName), ex);
             }

app/display/representation/src/main/java/org/csstudio/display/builder/representation/Preferences.java

@@ -22,6 +22,9 @@ public class Preferences
                       update_accumulation_time, update_delay, plot_update_delay, image_update_delay,
                       tooltip_length, embedded_timeout;
 
+    @Preference
+    public static double svg_rendering_resolution_factor;
+
     static
     {
     	AnnotatedPreferences.initialize(Preferences.class, "/display_representation_preferences.properties");

app/display/representation/src/main/resources/display_representation_preferences.properties

@@ -41,3 +41,21 @@ tooltip_length=200
 
 # Timeout for load / unload of Embedded Widget content [ms]
 embedded_timeout=5000
+
+# 'svg_rendering_resolution_factor' determines a factor
+# to multiply the rendering resolution of SVGs with.
+# E.g., to render SVGs at double the default resolution
+# both horizontally and vertically, the option can be
+# set to svg_rendering_resolution_factor=2.0. This option
+# can be useful to enable sharper rendering when zooming
+# in. However, the additional sharpness comes at the
+# cost of a significant increase in memory consumption,
+# as described in the next paragraph.
+#
+# IMPORTANT: The memory consumption scales as the square of
+# the value of 'svg_rendering_resolution_factor'! E.g.,
+# when svg_rendering_resolution_factor=2.0, then rendered SVGs
+# consume 4 times the memory compared to rendered SVGs when
+# svg_rendering_resolution_factor=1.0. For this reason,
+# this option should almost certainly be a very low number.
+svg_rendering_resolution_factor=1.0