Enable Drag and Drop between SubViewports and Windows #67531

Sauermann · 2022-10-17T11:20:36Z

Make Drag and Drop an application-wide operation.
This allows to drop on Controls in other Viewports/Windows.

Also now all nodes in the SceneTree are notified about the Drag and Drop operation, with the exception of SubViewports that are not child-nodes of SubViewportContainers. This distinction seemed prudent, because these SubViewports need to be displayed manually and this requires manual setup also for Drag and Drop.

Unit-tests for Drag and Drop in different Windows & SubViewports are also added.

In order to achieve this, the following changes were made:

Viewport::_update_mouse_over from Refactor mouse_entered and mouse_exited signals #67791 is used to identify the drop-target (even within nested viewports)
This Control is used as a basis for the Drop-operation, which replaces the previous algorithm, that was only aware of topmost Viewports.
In order to handle DnD within non-default SubViewports (see for an example Rewrite Gui in 3D demo to use Physics Picking for mouse events godot-demo-projects#925), it becomes necessary to track drag-operations in each (for the lack of a better name) section in the scene-tree.
is_directly_attached_to_screen is replaced by get_section_rootviewport. which is of the same complexity, but additionally returns the topmost Viewport within the section
_propagate_viewport_notification had to be adjusted to account for sections
DisplayServerX11::delete_sub_window needed to be adjusted similar to Fix crash on Windows when closing Window #80142, since the event-callback is also needed on linuxbsd during Window-deletion

Relations:

alternative to Fix drag notifications across windows. #71509 and has a broader scope
fix In-game Drag and Drop between viewports does not work #28522
fix Valid drop locations are not highlighted when inspector is made floating. #44390
fix Error emitting !get_viewport()->gui_is_dragging() when using set_drag_preview from a sub-window #59622
fix Drag and drop in window does not work if there is a sibling window presents at specific positions #77665
fix no longer (will be done separately) Drag previews clipped by Popup that created them #67186
fix duplicate Godot 4 Unable to drag from Window / Popup #62384
fix duplicate _can_drop_data not called in sub-viewports #68063
was previously blocked by [unittests] Send Mouse events via DisplayServer instead of push_input #71972
utilizes Refactor mouse_entered and mouse_exited signals #67791
follow-up to Fix crash on Windows when closing Window #80142
related to Allow drag_preview to be handled by a different viewport than its parent #64949
related to "mouse_entered" and "mouse_exited" signals are broken while holding down a mouse button #20881

MRP: BugDragNDrop.zip (updated 2023-01-20)

The Drag-Preview in the following Video is outdated, because that will be done in a different PR.

BugDragNDrop.mp4

Updated 2023-01-28: Fix merge conflict
Updated 2023-03-20: Fix merge conflict
Updated 2023-05-30: Linked another bug-report, that this PR fixes. Resolve problematic testcases. Fix merge conflict.
Updated 2023-06-07: Fix merge conflict
Updated 2023-06-08: Fix issue with docks
Updated 2023-06-19: Fix issue with simultaneous drag starts
Updated 2023-07-06: Fix issue with Gui in 3D Demo, Add Unit-tests
Updated 2023-07-19: Fix merge conflict
Updated 2023-08-02: Fix merge conflict with #67791 and #79805
Updated 2023-08-12: Fix merge conflict
Updated 2023-09-18: Fix merge conflict with #81551
Updated 2024-01-03: Fix merge conflict with #86511 and verified that #86493 doesn't get reintroduced.
Updated 2024-05-03: Rebased after #91425 and verified that #91387 doesn't get reintroduced.
Updated 2024-09-15: Rebased after 4.3-release for good measure and verified the functionality in the MRP.

rokiyo · 2022-10-17T21:31:00Z

Fixes #67186
Potentially supersedes #64949 ?

Sauermann · 2022-10-17T21:33:20Z

@rokiyo Thanks, I did not see these.

scene/main/viewport.cpp

bruvzg

Seems to be working fine.

Note: At least on macOS, mouse cursor is changed to <-> when crossing resizable window border, and not restored to DnD cursor afterwards (until drop target is hovered).

scene/main/viewport.cpp

Sauermann · 2022-10-20T09:08:34Z

Note: At least on macOS, mouse cursor is changed to <-> when crossing resizable window border, and not restored to DnD cursor afterwards (until drop target is hovered).

That sounds like Godot believes that the mouse cursor is still FORBIDDEN while macOS changed it to RESIZE.
I believe that this is a platform-specific problem, that should be fixed in the macOS-DisplayServer?

scene/main/viewport.cpp

Sauermann · 2022-10-23T11:57:23Z

This implementation could be greatly simplified, if the functionality of #67791 was available.
Converting to draft, until a decision on #67791 is made.

Chaosus · 2023-01-14T14:57:09Z

@Sauermann how is your progress with this PR?

Sauermann · 2023-01-14T15:53:57Z

@Chaosus
This PR is blocked by progress on #67791, which is waiting on reviews.
Both implement the same algorithm in different locations and #67791 implements it in a location, where it additionally fixes several bugs (which can not be fixed by this PR). So my recommendation would be to review and merge #67791 before I continue working on this PR.

Also #58334 will cause a few small adjustments to this PR, but I consider them minor. Ideally I would prefer, that #58334 should be merged before this PR, but that is not strictly necessary.

reduz · 2023-01-17T12:29:47Z

I wrote #71509 as a far simpler way to solve this. I believe It fixes drags/drops accross viewports more elegantly. What is missing is proper drag previews across windows, but the correct solution to this in my mind is to use borderless, transparent, passthrough windows similar to what we use with tooltips.

Sauermann · 2023-01-17T14:40:09Z

The complexity in this PR comes from the fact that is solves three problems:

Drag and Drop in different Windows/SubViewports
Drag-Preview in different Viewports (The idea of using borderless, transparent, passthrough windows is superior to my own current approach)
Fix mouse-enter-exit-signals during Drag and Drop

In order to be able to compare it with #71509 (which aims to solve 1), I believe, that I should extract the part of this PR, that solves 1, so that they can be compared better. It looks like I am struggling again with packing too much content into a single PR.

From a quick comparison, this approach makes Drag and Drop an application-wide operation, while #71509 uses a heuristic to determine a Viewport to use as a base for the Drag and Drop operation.

akien-mga · 2023-08-17T09:38:41Z

Could use testing on macOS (and review if you can) @bruvzg

EiTaNBaRiBoA · 2023-10-03T08:33:23Z

This is if not the most important feature to distinguish between flutter and godot.
If godot will support it, it literally ends flutter, wpf, Qt and many more. I work as a software engineer and multi window communication is a deal breaker for many companies. This feature solves it and bring plenty of possibilities in the future. Please add this

akien-mga

Looks good to me. Let's merge if you think now would be a good time.

doc/classes/Viewport.xml

scene/main/viewport.cpp

scene/main/viewport.h

tests/scene/test_viewport.h

scene/main/viewport.h

akien-mga · 2024-02-14T11:53:00Z

We decided to keep this for the 4.4 cycle, as it's pretty late now in the 4.3 cycle and this PR changes behavior in a way that may clash with user expectations. So we don't want to rush it / have to reconsider the design during the 4.3 beta/RC stage.

Make Drag and Drop an application-wide operation. This allows do drop on Controls in other Viewports/Windows. In order to achieve this, `Viewport::_update_mouse_over` is adjusted to remember the Control, that the mouse is over (possibly within nested viewports). This Control is used as a basis for the Drop-operation, which replaces the previous algorithm, which was only aware of the topmost Viewport. Also now all nodes in the SceneTree are notified about the Drag and Drop operation, with the exception of SubViewports that are not children of SubViewportContainers.

akien-mga · 2024-09-16T09:40:36Z

So now would be a good time to merge this for 4.4 I think?

akien-mga · 2024-09-16T11:52:03Z

Thanks!

Sauermann requested a review from a team as a code owner October 17, 2022 11:20

Chaosus added enhancement topic:core topic:porting labels Oct 17, 2022

Chaosus added this to the 4.0 milestone Oct 17, 2022

Sauermann force-pushed the fix-drag-n-drop branch from 9c955b3 to 1b2ea91 Compare October 17, 2022 14:38

Sauermann requested a review from a team as a code owner October 17, 2022 14:38

Sauermann force-pushed the fix-drag-n-drop branch 4 times, most recently from efe0752 to 1f07643 Compare October 19, 2022 23:20

Sauermann commented Oct 19, 2022

View reviewed changes

scene/main/viewport.cpp Show resolved Hide resolved

bruvzg approved these changes Oct 20, 2022

View reviewed changes

scene/main/viewport.cpp Outdated Show resolved Hide resolved

Sauermann force-pushed the fix-drag-n-drop branch 2 times, most recently from 6b25c96 to a52d416 Compare October 20, 2022 09:07

Sauermann force-pushed the fix-drag-n-drop branch from a52d416 to c20e855 Compare October 20, 2022 09:16

mhilbrunner added the bug label Oct 21, 2022

Sauermann commented Oct 21, 2022

View reviewed changes

scene/main/viewport.cpp Outdated Show resolved Hide resolved

Sauermann marked this pull request as draft October 23, 2022 11:57

Sauermann mentioned this pull request Oct 30, 2022

_can_drop_data not called in sub-viewports #68063

Closed

Sauermann mentioned this pull request Nov 29, 2022

Allow drag_preview to be handled by a different viewport than its parent #64949

Closed

Sauermann mentioned this pull request Jan 16, 2023

Fix drag notifications across windows. #71509

Closed

KoBeWi approved these changes Aug 13, 2023

View reviewed changes

Sauermann mentioned this pull request Aug 21, 2023

Chance of crash when Control overrides mouse input on Area2D #79371

Closed

Sauermann force-pushed the fix-drag-n-drop branch from 82cb5f9 to 70b3d18 Compare September 18, 2023 19:14

akien-mga modified the milestones: 4.2, 4.3 Sep 19, 2023

Sauermann mentioned this pull request Oct 16, 2023

Fix dragging in mesh preview will create a "drag and drop" action #83425

Closed

Sauermann mentioned this pull request Nov 9, 2023

Consider children Control nodes for mouse-enter/exit notifications #83276

Closed

Sauermann mentioned this pull request Dec 25, 2023

can_drop_data with embedded subwindows disabled ignores viewport content_scale_factor #86493

Closed

Sauermann force-pushed the fix-drag-n-drop branch 2 times, most recently from 0f9ae17 to 277584e Compare January 3, 2024 10:10

akien-mga approved these changes Feb 14, 2024

View reviewed changes

AThousandShips reviewed Feb 14, 2024

View reviewed changes

scene/main/viewport.h Outdated Show resolved Hide resolved

akien-mga modified the milestones: 4.3, 4.4 Feb 14, 2024

Sauermann force-pushed the fix-drag-n-drop branch from 277584e to 9d418e8 Compare February 18, 2024 08:54

This was referenced Feb 18, 2024

Redirect mouse events to the window under cursor, simplify popup menu input processing. #88392

Open

Ending a dragging operation basically never updates the cursor shape #88678

Open

Chaosus mentioned this pull request Feb 25, 2024

Implement GraphFrame and integrate it in VisualShader #88014

Merged

3 tasks

Sauermann force-pushed the fix-drag-n-drop branch from 9d418e8 to 6bc76a9 Compare May 3, 2024 17:59

RedMser mentioned this pull request May 27, 2024

Release mouse button presses on window focus change. #92419

Closed

kitbdev mentioned this pull request Aug 16, 2024

Can't drag things between monitors anymore since 4.3 #95639

Closed

Hilderin mentioned this pull request Aug 16, 2024

Fix drag&drop between window on Windows #95665

Merged

Sauermann force-pushed the fix-drag-n-drop branch from 6bc76a9 to 60aaa01 Compare September 14, 2024 23:09

akien-mga merged commit b92fe32 into godotengine:master Sep 16, 2024
20 checks passed

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Enable Drag and Drop between SubViewports and Windows #67531

Enable Drag and Drop between SubViewports and Windows #67531

Sauermann commented Oct 17, 2022 •

edited

Loading

rokiyo commented Oct 17, 2022

Sauermann commented Oct 17, 2022

bruvzg left a comment

Sauermann commented Oct 20, 2022 •

edited

Loading

Sauermann commented Oct 23, 2022

Chaosus commented Jan 14, 2023

Sauermann commented Jan 14, 2023 •

edited

Loading

reduz commented Jan 17, 2023

Sauermann commented Jan 17, 2023

akien-mga commented Aug 17, 2023

EiTaNBaRiBoA commented Oct 3, 2023

akien-mga left a comment

akien-mga commented Feb 14, 2024 •

edited

Loading

akien-mga commented Sep 16, 2024

akien-mga commented Sep 16, 2024

Enable Drag and Drop between SubViewports and Windows #67531

Enable Drag and Drop between SubViewports and Windows #67531

Conversation

Sauermann commented Oct 17, 2022 • edited Loading

rokiyo commented Oct 17, 2022

Sauermann commented Oct 17, 2022

bruvzg left a comment

Choose a reason for hiding this comment

Sauermann commented Oct 20, 2022 • edited Loading

Sauermann commented Oct 23, 2022

Chaosus commented Jan 14, 2023

Sauermann commented Jan 14, 2023 • edited Loading

reduz commented Jan 17, 2023

Sauermann commented Jan 17, 2023

akien-mga commented Aug 17, 2023

EiTaNBaRiBoA commented Oct 3, 2023

akien-mga left a comment

Choose a reason for hiding this comment

akien-mga commented Feb 14, 2024 • edited Loading

akien-mga commented Sep 16, 2024

akien-mga commented Sep 16, 2024

Sauermann commented Oct 17, 2022 •

edited

Loading

Sauermann commented Oct 20, 2022 •

edited

Loading

Sauermann commented Jan 14, 2023 •

edited

Loading

akien-mga commented Feb 14, 2024 •

edited

Loading