[SVG Sprite] Improve Fill Color Management Of Inline SVG Sprites
Context
The current implementation of inline SVG sprites in PlantUML has some limitations when it comes to fill color management. This issue is particularly noticeable when the default fill color of the SVG sprite is not the same as the line color of the hosted element. In this article, we will discuss the current issues and propose some improvements to enhance the fill color management of inline SVG sprites.
Wanted Feature
The main goal of this feature is to improve the fill color management of inline SVG sprites. This includes:
- Fixing the default fill color when the line color of the hosted element is white
- Resolving issues where sprites disappear in certain diagrams
- Ensuring that the fill color is consistent across different diagrams
Current Issues
Default Fill Color
By default, if an SVG path does not have a fill field, the default fill color is #000000 (black). However, on the PlantUML side, the default fill color seems to be the line color of the hosted element. This can lead to inconsistent fill colors across different diagrams.
Sprites Disappear
In certain diagrams, such as Activity diagrams, the sprites may disappear due to the way the fill color is managed. This is a major issue that needs to be addressed.
Inconsistent Fill Color
The fill color of the sprites is not consistent across different diagrams. This can lead to a confusing and inconsistent visual representation of the diagrams.
Proposed Improvements
Fix Default Fill Color
To fix the default fill color issue, we can modify the SvgNanoParser class to set the default fill color to the line color of the hosted element when the line color is not white. This will ensure that the fill color is consistent across different diagrams.
// SvgNanoParser.java
public class SvgNanoParser {
// ...
public void parseSprite(SvgSprite sprite) {
// ...
if (sprite.getLine().getColor() != Color.WHITE) {
sprite.setFill(sprite.getLine().getColor());
}
// ...
}
}
Resolve Issues with Disappearing Sprites
To resolve the issue with disappearing sprites, we can modify the Sprite class to check if the fill color is set before rendering the sprite. If the fill color is not set, we can use the default fill color.
// Sprite.java
public class Sprite {
// ...
public void render() {
if (getFill() == null) {
setFill(Color.BLACK); // default fill color
}
// ...
}
}
Ensure Consistent Fill Color
To ensure that the fill color is consistent across different diagrams, we can modify the Diagram class to set the fill color of all sprites to the same value.
// Diagram.java
public class Diagram {
// ...
public void render() {
// ...
for (Sprite sprite : getSprites()) {
sprite.setFill(getLineColor());
}
// ...
}
}
Conclusion
In conclusion, the current implementation of inline SVG sprites in PlantUML has some limitations when it comes to fill color management. By proposing some improvements, we can enhance the fill color of inline SVG sprites and ensure that the fill color is consistent across different diagrams. These improvements include fixing the default fill color, resolving issues with disappearing sprites, and ensuring consistent fill color across different diagrams.
References
Example Use Cases
Fix Default Fill Color
@startuml
sprite bs1 <svg viewBox="0 0 16 16">
<path d="M16 8A8 8 0 1 1 0 8a8 8 0 0 1 16 0M9.283 4.002H7.971L6.072 5.385v1.271l1.834-1.318h.065V12h1.312z"/>
</svg>
title This is a title with SVG sprite: <$bs1>!
footer A footer with <$bs1> !
legend <$bs1>
@enduml
Resolve Issues with Disappearing Sprites
@startuml
sprite bs1 <svg viewBox="0 0 16 16">
<path d="M16 8A8 8 0 1 1 0 8a8 8 0 0 1 16 0M9.283 4.002H7.971L6.072 5.385v1.271l1.834-1.318h.065V12h1.312z"/>
</svg>
legend <$bs1>
:<$bs1>;
-> sprite: <$bs1>;
:a;
-[#red]->sprite: <$bs1>;
:b;
@enduml
Ensure Consistent Fill Color
@startuml
sprite bs1 <svg viewBox="0 0 16 16">
<path d="M16 8A8 8 0 1 1 0 8a8 8 0 0 1 16 0M9.283 4.002H7.971L6.072 5.385v1.271l1.834-1.318h.065V12h1.312z"/>
</svg>
card "<$bs1>" as bs1
card a
card b
bs1 --> a : sprite: <$bs1>
a --> b #red: sprite: <$bs1>
legend <$bs1>
footer 1.2025.2 / %version()
@enduml
```<br/>
**Q&A: Improve Fill Color Management of Inline SVG Sprites**
=====================================================
**Q: What is the current issue with fill color management of inline SVG sprites in PlantUML?**
-----------------------------------------------------------------------------------------
A: The current implementation of inline SVG sprites in PlantUML has some limitations when it comes to fill color management. By default, if an SVG `path` does not have a `fill` field, the default fill color is `#000000` (black). However, on the PlantUML side, the default fill color seems to be the line color of the hosted element. This can lead to inconsistent fill colors across different diagrams.
**Q: How can I fix the default fill color issue?**
------------------------------------------------
A: To fix the default fill color issue, you can modify the `SvgNanoParser` class to set the default fill color to the line color of the hosted element when the line color is not white. This will ensure that the fill color is consistent across different diagrams.
```java
// SvgNanoParser.java
public class SvgNanoParser {
// ...
public void parseSprite(SvgSprite sprite) {
// ...
if (sprite.getLine().getColor() != Color.WHITE) {
sprite.setFill(sprite.getLine().getColor());
}
// ...
}
}
Q: What is the issue with disappearing sprites in certain diagrams?
A: In certain diagrams, such as Activity diagrams, the sprites may disappear due to the way the fill color is managed. This is a major issue that needs to be addressed.
Q: How can I resolve the issue with disappearing sprites?
A: To resolve the issue with disappearing sprites, you can modify the Sprite class to check if the fill color is set before rendering the sprite. If the fill color is not set, you can use the default fill color.
// Sprite.java
public class Sprite {
// ...
public void render() {
if (getFill() == null) {
setFill(Color.BLACK); // default fill color
}
// ...
}
}
Q: How can I ensure that the fill color is consistent across different diagrams?
A: To ensure that the fill color is consistent across different diagrams, you can modify the Diagram class to set the fill color of all sprites to the same value.
// Diagram.java
public class Diagram {
// ...
public void render() {
// ...
for (Sprite sprite : getSprites()) {
sprite.setFill(getLineColor());
}
// ...
}
}
Q: What are the benefits of improving fill color management of inline SVG sprites?
A: The benefits of improving fill color management of inline SVG sprites include:
- Consistent fill colors across different diagrams
- Improved visual representation of diagrams
- Reduced confusion and errors due to inconsistent fill colors
Q: How can I implement these improvements in my PlantUML project?
A: To implement these improvements in your PlantUML project, you can follow these steps:
- Modify the
SvgNanoParserclass to set the default fill color to the line color of the hosted element when the line color is not white. - Modify the
Spriteclass to check if the fill color is set before rendering the sprite. If the fill color is not set, use the default fill color. - Modify the
Diagramclass to set the fill color of all sprites to the same value.
Q: What are the potential issues with implementing these improvements?
A: The potential issues with implementing these improvements include:
- Inconsistent fill colors across different diagrams
- Confusion and errors due to inconsistent fill colors
- Potential performance issues due to additional processing required to set the fill color
Q: How can I troubleshoot issues with fill color management of inline SVG sprites?
A: To troubleshoot issues with fill color management of inline SVG sprites, you can:
- Check the fill color of each sprite in the diagram
- Verify that the fill color is set correctly in the
SvgNanoParserclass - Check for any inconsistencies in the fill color across different diagrams
Q: What are the best practices for implementing fill color management of inline SVG sprites?
A: The best practices for implementing fill color management of inline SVG sprites include:
- Consistently setting the fill color across different diagrams
- Using a default fill color when the fill color is not set
- Verifying that the fill color is set correctly in the
SvgNanoParserclass