v3: Window maximum width and height issues on Linux Wayland

[VirxEC]

Description

Same as #2431 but on Wails v3 - this previous issue was closed when #4047 was merged, but the PR only fixed the issue for Wails v2.

To Reproduce

Same as #2431

Expected behaviour

Same as #2431

Screenshots

Same as #2431

Attempted Fixes

No response

System Details

Wails (v3.0.0-alpha.10)  Wails Doctor 
                                                                                                                                                                                                                                                                                                                                                                           
# System 

┌─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
| Name         | Ubuntu                                                                                                               |
| Version      | 24.04                                                                                                                |
| ID           | ubuntu                                                                                                               |
| Branding     | 24.04.2 LTS (Noble Numbat)                                                                                           |
| Platform     | linux                                                                                                                |
| Architecture | amd64                                                                                                                |
| CPU          | AMD Ryzen 9 5900X 12-Core Processor                                                                                  |
| GPU 1        | Navi 22 [Radeon RX 6700/6700 XT/6750 XT / 6800M/6850M XT] (Advanced Micro Devices, Inc. [AMD/ATI]) - Driver: amdgpu  |
| Memory       | 32GB                                                                                                                 |
└─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘

# Build Environment 

┌────────────────────────────────┐
| Wails CLI    | v3.0.0-alpha.10 |
| Go Version   | go1.24.1        |
| -buildmode   | exe             |
| -compiler    | gc              |
| CGO_CFLAGS   |                 |
| CGO_CPPFLAGS |                 |
| CGO_CXXFLAGS |                 |
| CGO_ENABLED  | 1               |
| CGO_LDFLAGS  |                 |
| GOAMD64      | v1              |
| GOARCH       | amd64           |
| GOOS         | linux           |
└────────────────────────────────┘

# Dependencies 

┌──────────────────────────────────────┐
| gtk3       | 3.24.41-4ubuntu1.3      |
| npm        | 9.2.0                   |
| pkg-config | 1.8.1-2build1           |
| webkit2gtk | 2.48.3-0ubuntu0.24.04.1 |
| gcc        | 12.10ubuntu1            |
|                                      |
└────── * - Optional Dependency ───────┘

Additional context

No response

[dosubot]

Hi @VirxEC! I'm Dosu and I’m helping the wails team.

The window maximum width and height issue on Linux Wayland is still present in Wails v3. The fix that was merged for v2 has not been ported to v3, and there are currently no workarounds or v3-specific updates addressing this in the codebase or documentation. The Wails v3 docs describe the MaxWidth/MaxHeight options and related APIs, but do not mention Wayland-specific handling or limitations, and the underlying implementation for Wayland window sizing constraints from v2 is not present in v3 yet. Correct behavior will depend on a future port of the v2 patch or equivalent new code. Monitoring the repository and release notes for updates is recommended as this area evolves.
Reference: v3 docs and v2 implementation

To reply, just mention @dosu.

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[leaanthony]

This issue was fixed by PR #4561 which was merged on September 25, 2025.

The fix introduced a monitor-window search fallback for Wayland that properly handles window sizing constraints.

Please update to the latest v3-alpha to get this fix. If you're still experiencing issues, please reopen this issue with details.

[leaanthony]

Ported the v2 fix (PR #4047) to v3 in PR #4778.

The fix calculates and caches the window decorator offset (difference between GTK's allocated size and actual window size) on Wayland, then adds this offset to max width/height constraints. This allows fullscreen and maximize to properly fill the screen.

[leaanthony]

Testing the Fix

To test this fix before it's merged, you can use the branch directly:

# In your go.mod, replace the wails module with the fix branch:
go mod edit -replace github.com/wailsapp/wails/v3=github.com/wailsapp/wails/v3@fix-4429-wayland-maxsize

# Or clone and test directly:
git clone -b fix-4429-wayland-maxsize https://github.com/wailsapp/wails.git
cd wails/v3
go build ./...

What to verify on Wayland:

1. Create a window with MaxWidth and MaxHeight options set
2. Try to maximize the window - it should now fill the screen properly
3. Try fullscreen - it should fill the entire display

Expected behavior:

• On Wayland: Window should maximize/fullscreen to fill the screen, accounting for window decorations
• On X11: Behavior should be unchanged (decorator offset will be 0)

Please let me know if this resolves the issue for you!