On Tue, 25 Nov 2025 18:58:14 GMT, Michael Strauß <[email protected]> wrote:
> This enhancement allows `Stage` to be placed on the screen similar to a popup
> window, where a user-specified positioning anchors defines a point on the
> stage that should coincide with a given location on the screen. For this
> purpose, the following new methods are added to `Stage`:
>
>
> public class Stage {
> public void relocate(AnchorPoint screenAnchor, AnchorPoint stageAnchor);
> public void relocate(AnchorPoint screenAnchor, Insets screenPadding,
> AnchorPoint stageAnchor, AnchorPolicy);
> public void relocate(Screen, AnchorPoint screenAnchor, Insets
> screenPadding, AnchorPoint stageAnchor, AnchorPolicy);
> }
>
>
> ## AnchorPoint
> `AnchorPoint` is a point that is either specified in absolute coordinates, or
> relative to the screen or stage:
>
> var anchor1 = AnchorPoint.proportional(0.5, 0.5); // center of the
> screen/stage
> var anchor2 = AnchorPoint.absolute(100, 100); // absolute coordinates within
> screen/stage
>
>
> For example, a stage that sits flush with the bottom-right corner of the
> screen can be shown as follows:
>
> var screenAnchor = AnchorPoint.proportional(1, 1); // or use the
> AnchorPoint.BOTTOM_RIGHT constant
> var stageAnchor = AnchorPoint.proportional(1, 1);
> stage.relocate(screenAnchor, stageAnchor);
> stage.show();
>
>
> ## AnchorPolicy
> `AnchorPolicy` controls how the anchor may be adjusted when the preferred
> placement doesn't fit within the screen bounds:
>
>
> public enum AnchorPolicy {
> FIXED,
> FLIP_HORIZONTAL,
> FLIP_VERTICAL,
> AUTO
> }
>
>
> * `FIXED`: always use the provided anchor; only adjust the resulting position
> to fit within the screen.
> * `FLIP_HORIZONTAL`: if the preferred placement violates horizontal
> constraints, try a horizontally flipped anchor (e.g. top-left to top-right)
> before falling back to the original anchor.
> * `FLIP_VERTICAL`: likewise for vertical constraints.
> * `AUTO`: automatically choose the most suitable flip:
> if only horizontal constraints are violated, acts like `FLIP_HORIZONTAL`;
> if only vertical constraints are violated, acts like `FLIP_VERTICAL`;
> if both are violated, try a diagonally flipped anchor (both axes) and pick
> the placement that requires the least adjustment.
>
> This is useful for popup-like behavior where you have a preferred "opening
> direction", but want the window to flip to the opposite side of the reference
> point when there isn’t enough space (e.g. "prefer below, but open above if
> below doesn’t fit").
>
> ### PopupWindow support
> The new `PopupWindow.anchorPolicy` property adds the same "flip the anchor
> when it...
modules/javafx.graphics/src/main/java/com/sun/javafx/stage/WindowRelocator.java
line 105:
> 103: } else {
> 104: gravityX = stageAnchor.getX() / windowWidth;
> 105: gravityY = stageAnchor.getY() / windowHeight;
It might be a good idea to explain what "gravity" is, maybe in
`ComputedLocation` or `WindowLocationAlgorithm`.
Here, for example, L101 tells us the gravity is measured in pixels, while L104
indicates the gravity is dimensionless.
modules/javafx.graphics/src/main/java/javafx/stage/Stage.java line 1322:
> 1320: * @since 26
> 1321: */
> 1322: public final void relocate(Screen screen, AnchorPoint screenAnchor,
> Insets screenPadding,
would it be conceptually simpler to offer just one new method with all the
possible parameters (screen anchors, insets) instead of several? I presume
these new methods will be rarely used.
or, if there is one frequent case, provide an additional utility method for
that case?
-------------
PR Review Comment: https://git.openjdk.org/jfx/pull/1986#discussion_r2608315565
PR Review Comment: https://git.openjdk.org/jfx/pull/1986#discussion_r2608469098
