viewer

Viewer for Slint

This program is a viewer for .slint files from the Slint Project.

Installation

The viewer can be installed from crates.io:

cargo install slint-viewer

Alternatively, you can download one of our pre-built binaries for Linux or Windows:

1. Open https://github.com/slint-ui/slint/releases
2. Click on the latest release
3. From "Assets" download either slint-viewer-linux.tar.gz for a Linux x86-64 binary or slint-viewer-windows.zip for a Windows x86-64 binary.
4. Uncompress the downloaded archive and run slint-viewer/slint-viewer.exe.

Usage

You can open .slint files by just passing it as an argument:

slint-viewer path/to/myfile.slint

Command line arguments

• --auto-reload: Automatically watch the file system, and reload when it changes
• --save-data <file>: When exiting, write the value of public properties to a json file. Only property whose types can be serialized to json will be written. This option is incompatible with --auto-reload
• --load-data <file>: Load the values of public properties from a json file.
• -I <path>: Add an include path to look for imported .slint files or images.
• -L <library=path>: Add a library path to look for @library imports.
• --style <style>: Set the style. Defaults to fluent on all platforms
• --backend <backend>: Override the Slint rendering backend
• --on <callback> <handler>: Set a callback handler, see callback handler
• --component <name>: Load the component with the given name. If not specified, load the last exported component
• --screenshot <file>: Render the component to an image file and exit instead of opening a window. The file format is inferred from the extension (e.g. .png, .jpg). Use - to write a PNG to standard output. The component is rendered at its preferred size with a headless renderer (Skia's software rasterizer when the renderer-skia feature is enabled, otherwise Slint's software renderer), unless --backend is also given. Set SLINT_SCALE_FACTOR to override the default scale factor of 1. This option is incompatible with --auto-reload.

Instead of a path to a file, one can use - for the standard input or the standard output.

Callback handler

It is possible to tell the viewer to execute some shell commands when a callback is received. You can use the --on command line argument, followed by the callback name, followed by the command. Within the command arguments, $1, $2, ... will be replaced by the first, second, ... argument of the callback. These will be shell escaped.

Example: Imagine we have a myfile.slint looking like this:

export component MyApp inherits Window {
  callback open-url(string);
  //...
}

It is possible to make the open-url callback to execute a command by doing

slint-viewer --on open-url 'xdg-open $1' myfile.slint

Be careful to use single quote or to escape the $ so that the shell don't expand the $1

Dialogs

If the root element of the .slint file is a Dialog, the different StandardButton might close the dialog if no callback was set on the button.

• ok, yes, or close buttons accepts the dialog
• cancel, no buttons reject the dialog

Result code

The program returns with the following error code:

• If the command line argument parsing fails, the exit code will be 1
• If the .slint compilation fails, the compilation error will be printed to stderr and the exit code will be -1
• If a Window is closed, the exit code will be 0
• If a Dialog is closed with the "Ok" or "Closed" or "Yes" button, the exit code will be 0
• If a Dialog is closed with the "Cancel" or "No" button, or using the close button in the window title bar, the exit code will be 1

Examples

slint-viewer can be used to display an GUI from a shell script. For examples check out the examples/bash folder in our repository.

Building for iOS

On iOS the viewer lets you preview .slint files from your editor directly on an iPhone, iPad, or the simulator.

Prerequisites

• A computer running macOS with an up-to-date installation of Xcode.
• Xcodegen (e.g. brew install xcodegen).
• Rust with the iOS toolchains: rustup target add aarch64-apple-ios aarch64-apple-ios-sim.

Build and run

Generate the Xcode project and open it:

cd tools/viewer
xcodegen generate --spec ios-project.yml
open "Slint Viewer.xcodeproj"

From Xcode, build and run on the simulator or a device.