The Servo Browser Engine
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Mukilan Thiyagarajan ba67a0a4fb
servoshell: fix issues related to HiDPI (#33529)
The current implementation has 3 main issues related to HiDPI:

1. When the window moves from a screen with scale factor of 1.5 to one
   with 1 and back to 1.5, the minibrowser toolbar actually ends up
   being scaled by a factor of 2.25 instead of 1.5. This is because we
   currently use the [set_pixels_per_point] method on egui's Context,
   but calling this with a value of `ppp` will modify egui's internal
   'zoom factor' to be:
   ```
   zoom_factor = ppp / native_points_per_pixel.
   ```
   where `native_points_per_pixel` is the window system scale factor.
   The idea is egui can calculate the final scale factor for translating
   its logical points to physical pixels as:
   ```
   points_per_pixel = zoom_factor * native_points_per_pixel
   ```
   where zoom_factor is a factor used for Ctrl+Plus, Ctrl+Minus
   behaviour. The problem is when we handle the ScaleFactorChanged winit
   event due to window moving between screens, the
   `native_points_per_pixel` still has the value of the previous
   screen's native scaling factor and not the current screen's factor.
   This seems to be the case even if we pass the ScaleFactorChanged
   event to egui before we call `set_pixels_per_point`.
2. The egui logic for handing Ctrl+Plus, Ctrl+Minus and Ctrl+0 doesn't
   interact well with servoshell's device-pixel-ratio CLI argument which
   allows the user to override the HiDPI factor. For example, Ctrl+0
   will cause egui to reset the zoom_factor to 1.0 instead of the
   override we wanted. Another issue is egui's Ctrl+Plus/Ctrl+Minus
   will scale the minibrowser in increments of 0.10 whereas
   Servo's own page zoom doesn't (it keeps multiplying by 1.1, so the
   actual increments are 0.1, 0.21. 0.33 etc)
3. The inital window size calculation on Linux currently assumes a scale
   factor of 1.0. This means the window doesn't have the expected
   default logical size of 1024*740 on HiDPI systems. On a screen with
   HiDPI factor of 1.5, the logical window size ends up being 682x493.

This change addresses all 3 issues:

For 1,  switch to the `set_zoom_factor` method of egui context
to avoid the issue with scaling by incorrect native_points_per_pixel.
To allow for the device-pixel-ratio override to work, we calculate the
actual zoom_factor as `device-pixel-ratio / window's scaling factor`.

For 2, disable egui's handling of Ctrl+Plus, Ctrl+Minus, Ctrl-0
shortcuts. It is unclear whether the current behaviour of scaling
both the toolbar and the web page was intentional, or just an accident.
This behaviour is also different from other browser where page zoom
doesn't scale the GUI, so it doesn't seem like a regression to me.

For 3, use LogicalSize type of winit which lets the physical size
calulation to be handled by winit using the windows's actual HiDPI
factor instead of hardcoded 1.0.

[set_pixels_per_point]: 1603f05818/crates/egui/src/context.rs (L1886)

Signed-off-by: Mukilan Thiyagarajan <mukilan@igalia.com>
2024-09-24 12:12:23 +00:00
.cargo Make crown optional (#32494) 2024-06-24 11:46:43 +00:00
.github openharmony: add servoshell for ohos (#33295) 2024-09-20 08:20:27 +00:00
.vscode Format toml files (#30112) 2023-08-17 15:07:43 +00:00
components Layout: Implement innerText/outerText (#33312) 2024-09-24 09:45:33 +00:00
docs Update in-tree docs to point to the new book (#32743) 2024-07-09 15:42:00 +00:00
etc Update Rust to 1.80.1 (#33008) 2024-08-12 11:40:46 +00:00
ports/servoshell servoshell: fix issues related to HiDPI (#33529) 2024-09-24 12:12:23 +00:00
python ohos: Bundle resource files in hap (#33513) 2024-09-24 04:29:53 +00:00
resources servoshell: Update gilrs version, enable gamepad pref by default (#33466) 2024-09-17 05:52:19 +00:00
support ohos: Bundle resource files in hap (#33513) 2024-09-24 04:29:53 +00:00
tests Layout: Implement innerText/outerText (#33312) 2024-09-24 09:45:33 +00:00
third_party Update WebIDL.py (#32495) 2024-06-15 04:22:42 +00:00
.clang-format Run test-tidy on Windows 2019-11-21 09:56:39 +01:00
.flake8 Improve formatting of Python files (#30919) 2023-12-24 23:58:37 +00:00
.gitattributes openharmony: add servoshell for ohos (#33295) 2024-09-20 08:20:27 +00:00
.gitignore Add initial support for tracing and tracing-perfetto (#33188) 2024-09-04 08:24:29 +00:00
.mailmap Update Tetsuharu OHZEKI's entry in mailmap 2019-11-15 00:46:45 +09:00
Cargo.lock build(deps): bump quick-xml from 0.36.1 to 0.36.2 (#33524) 2024-09-23 19:16:38 +00:00
Cargo.toml chore: Update wgpu (#33506) 2024-09-21 04:20:18 +00:00
CLOBBER Add clobber mechanism 2017-05-08 16:19:56 +02:00
CODE_OF_CONDUCT.md Clarify the Code of Conduct (closes servo/servo.org#164) (#32835) 2024-07-23 09:12:03 +00:00
CONTRIBUTING.md Update in-tree docs to point to the new book (#32743) 2024-07-09 15:42:00 +00:00
deny.toml Add cargo-deny to mach-tidy to check license compliance. (#32465) 2024-06-12 09:54:45 +00:00
Info.plist remove bhtml 2018-02-11 08:02:39 +01:00
LICENSE Update MPL license to https (part 1) 2018-11-19 14:46:43 +01:00
mach Make Android build optional on Nix (#31231) 2024-02-02 02:13:24 +00:00
mach.bat Make mach.bat request Python 3 2021-05-22 18:27:10 +09:00
PULL_REQUEST_TEMPLATE.md Minor pull request template cleanup 2018-12-08 13:11:37 -08:00
README.md Update mozjs (SpiderMonkey) to 128.0 (#32769) 2024-07-29 07:20:15 +00:00
rust-toolchain.toml CI: Add separate Lint&Tidy check and remove test-tidy from linux (#33150) 2024-08-23 08:58:12 +00:00
rustfmt.toml mach: Do not use unstable rust for rustfmt (#31441) 2024-02-28 13:53:04 +00:00
SECURITY.md Update new issue URL in SECURITY.md (#31698) 2024-03-15 15:03:49 +00:00
servo-tidy.toml servoshell: Update gilrs version, enable gamepad pref by default (#33466) 2024-09-17 05:52:19 +00:00
servobuild.example Add OpenHarmony support to mach and CI (#32507) 2024-06-17 11:27:23 +00:00
shell.nix Nix: allow nix-shell without explicit path to shell.nix (#32035) 2024-04-17 07:02:31 +00:00
taplo.toml Format toml files (#30112) 2023-08-17 15:07:43 +00:00

The Servo Parallel Browser Engine Project

Servo is a prototype web browser engine written in the Rust language. It is currently developed on 64-bit macOS, 64-bit Linux, 64-bit Windows, and Android.

Servo welcomes contribution from everyone. Check out The Servo Book to get started, or go to servo.org for news and guides.

Getting started

For more detailed build instructions, see the Servo book under Setting up your environment, Building Servo, and Building for Android.

macOS

  • Download and install python, Xcode, and brew
  • Install rustup: curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
  • Restart your shell to make sure cargo is available
  • Install the other dependencies: ./mach bootstrap
  • Build servoshell: ./mach build

Linux

  • Install curl and python:
    • Arch: sudo pacman -S --needed curl python python-pip
    • Debian, Ubuntu: sudo apt install curl python3-pip python3-venv
    • Fedora: sudo dnf install curl python3 python3-pip python3-devel
    • Gentoo: sudo emerge net-misc/curl dev-python/pip
  • Install rustup: curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
  • Restart your shell to make sure cargo is available
  • Install the other dependencies: ./mach bootstrap
  • Build servoshell: ./mach build

Windows

  • Download and install python, choco, and rustup
    • Be sure to select Quick install via the Visual Studio Community installer
  • In the Visual Studio Installer, ensure the following components are installed:
    • Windows 10 SDK (10.0.19041.0) (Microsoft.VisualStudio.Component.Windows10SDK.19041)
    • MSVC v143 - VS 2022 C++ x64/x86 build tools (Latest) (Microsoft.VisualStudio.Component.VC.Tools.x86.x64)
    • C++ ATL for latest v143 build tools (x86 & x64) (Microsoft.VisualStudio.Component.VC.ATL)
    • C++ MFC for latest v143 build tools (x86 & x64) (Microsoft.VisualStudio.Component.VC.ATLMFC)
  • Restart your shell to make sure cargo is available
  • Install the other dependencies: .\mach bootstrap
  • Build servoshell: .\mach build

Android

  • Ensure that the following environment variables are set:
    • ANDROID_SDK_ROOT
    • ANDROID_NDK_ROOT: $ANDROID_SDK_ROOT/ndk/26.2.11394342/ ANDROID_SDK_ROOT can be any directory (such as ~/android-sdk). All of the Android build dependencies will be installed there.
  • Install the latest version of the Android command-line tools to $ANDROID_SDK_ROOT/cmdline-tools/latest.
  • Run the following command to install the necessary components:
    sudo $ANDROID_SDK_ROOT/cmdline-tools/latest/bin/sdkmanager --install
     "build-tools;33.0.2" \
     "emulator" \
     "ndk;26.2.11394342" \
     "platform-tools" \
     "platforms;android-33" \
     "system-images;android-33;google_apis;x86_64"
    
  • Follow the instructions above for the platform you are building on