RFR: 8222210: JFXPanel popups open at wrong coordinates when using multiple hidpi monitors

[Andy Goryachev]

On Thu, 20 Oct 2022 14:37:04 GMT, Johan Vos <jvos at openjdk.org> wrote:

> The root problem is actually broader than stated in the JBS issue. This PR now translates screencoordinates from absolute coordinates into coordinates that take the platformScale into account. 
> The whole process is complicated by the fact that throughout our code, we use e.g. `x` and `y` without clearly stating if those are absolute, logical, screen or rendering coordinates. 
> I believe the most consistent approach is to have the different entry points (e.g. a Glass Window or a JFXPanel) to deal with platformScale before passing screen coordinates. This is already done in the Glass approach, and this PR does the same in JFXPanel. That means some code is duplicated, but since this is only about 12 lines, and said code lives in 2 different modules, I think it's not worth the hassle of moving that into e.g. the base module.

modules/javafx.swing/src/main/java/javafx/embed/swing/JFXPanel.java line 375:

> 373:         AffineTransform awtScales = graphicsConfiguration.getDefaultTransform();
> 374:         for (Screen screen : Screen.getScreens()) {
> 375:             if ((Math.abs(screen.getPlatformX() - awtBounds.getX() * awtScales.getScaleX()) < 0.001) &&

minor: would it be better to create a standard method?

isNearZero(double)?

although the value of the constant might depend on a situation.

modules/javafx.swing/src/main/java/javafx/embed/swing/JFXPanel.java line 385:

> 383:     }
> 384: 
> 385:     private Dimension2D getSwingToFxPixel(GraphicsConfiguration g, float wx, float wy) {

minor: convertSwingToFxPixel() ?

modules/javafx.swing/src/main/java/javafx/embed/swing/JFXPanel.java line 451:

> 449:         Dimension2D onScreen = getSwingToFxPixel(getGraphicsConfiguration(), e.getXOnScreen(), e.getYOnScreen());
> 450:         int fxXOnScreen = (int) onScreen.getWidth();
> 451:         int fxYOnScreen = (int) onScreen.getHeight();

question: should it be (int) or Math.round()?
also, coordinates can be negative - will it work then?

modules/javafx.swing/src/main/java/javafx/embed/swing/JFXPanel.java line 646:

> 644:                 Dimension2D fxcoord = getSwingToFxPixel(getGraphicsConfiguration(), p.x, p.y);
> 645:                 screenX = (int)fxcoord.getWidth();
> 646:                 screenY = (int)fxcoord.getHeight();

same question about negative coordinates.

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PR: https://git.openjdk.org/jfx/pull/924