sqweek/dialog

The dialog library supports the following platforms:

• OSX: Uses Cocoa (NSAlert, NSSavePanel, NSOpenPanel, NSApp). Requires macOS 10.6+ for NSApplicationActivationPolicyAccessory.
• Win32: Uses MessageBox, GetOpenFileName, and GetSaveFileName via the github.com/TheTitanrain/w32 package.
• Linux: Uses GTK's MessageDialog and FileChooserDialog via cgo. Requires GTK3 development packages installed on the system.

To build the project from source, run the following commands:

go mod download
go build

The dialog package uses a builder pattern to construct and launch dialogs. The general workflow is:

1. Call a top-level constructor function (Message, File, or Directory) to get a builder instance.
2. Optionally call configuration methods (like Title, Filter, or SetStartDir) to customize the dialog.
3. Call a launcher method (like YesNo, Info, Load, Save, or Browse) to display the dialog and retrieve the result.

If a user cancels or closes a dialog without making a selection, the launcher methods return ErrCancelled.

if dialog.MsgDlg("%s", "Do you want to continue?").YesNo() {
    // user pressed Yes
}

Use dialog.File() combined with .Save() to prompt the user for a destination filename. You can use .Filter(description, extension) to suggest specific file types and .Title(string) to set the dialog title.

If the user selects an existing file, the underlying platform will spawn a confirmation dialog to ask if they want to overwrite it.

filename, err := dialog.File().Filter("XML files", "xml").Title("Export to XML").Save()

Use dialog.Directory() to open a folder selection dialog. Use .Title(string) to set the window title and .Browse() to execute the dialog. It returns the path to the selected directory and an error.

directory, err := dialog.Directory().Title("Load images").Browse()

Use dialog.File() to initiate a file picker. Use .Filter(description, extension) to restrict file types (e.g., .mp3). Call .Load() to open the dialog.

If the user cancels or closes the dialog, filename will be an empty string and the error will be dialog.Cancelled.

filename, err := dialog.File().Filter("Mp3 audio file", "mp3").Load()

Use dialog.Message to create a message box. You can chain .Title(string) to set the window title. Calling .YesNo() at the end configures the dialog to show 'Yes' and 'No' buttons. The method returns true if the dialog was displayed and the user clicked 'Yes', and false otherwise.

ok := dialog.Message("%s", "Do you want to continue?").Title("Are you sure?").YesNo()

Use Directory() to create a *DirectoryBuilder for selecting a single folder.

Configuration:

• .Title(title string): Sets the dialog window title.
• .SetStartDir(dir string): Sets the initial directory to be used in the dialog.

Launcher:

• .Browse() (string, error): Spawns the directory selection dialog. Returns the selected directory path or ErrCancelled if the user cancels.

// Example: Selecting a folder
dir, err := dialog.Directory().
	Title("Select Project Folder").
	SetStartDir("/tmp").
	Browse()

if err != nil {
	if err == dialog.ErrCancelled {
		// user cancelled
	}
}

Use Message(format string, args ...interface{}) to create a *MsgBuilder. This allows you to format a message string similar to fmt.Printf.

Configuration & Launchers:

• .Title(title string): Sets the dialog window title.
• .YesNo() bool: Spawns a dialog with "Yes" and "No" buttons. Returns true if the user selected "Yes".
• .Info(): Spawns an information dialog with an info icon and an "Ok" button.
• .Error(): Spawns an error dialog with an error icon and an "Ok" button.

// Example: Yes/No dialog
if dialog.Message("Delete %s?", filename).Title("Confirm").YesNo() {
    // user pressed Yes
}

// Example: Info dialog
dialog.Message("Operation successful").Info()

When a user cancels a dialog or closes the window without selecting an option, the launcher methods return the dialog.ErrCancelled error. You should check for this specific error to distinguish between a user action and a legitimate system error.

var ErrCancelled = errors.New("Cancelled")