Type Driver

NewDriver creates a driver for config, painting into canvas (a fresh canvas when nil). The first frame has been painted when it returns.

Advance moves virtual time forward by duration, repainting at frame cadence while an animation is in flight and applying background wakes. An idle application repaints nothing, as in a window.

Chord delivers a modified printable character. Control and Meta chords are raw key events whose Text is the base character (Control+C is Key unknown, Text "c"). Alt is raw only when the focused terminal requested AltSendsEscape and no input-method composition is active. It fails unless a terminal has the keyboard. Characters typed with only Shift are text.

Click moves to a point and presses and releases the primary button.

ClickButton moves to a point and presses and releases the given button once: ui.PointerButtonSecondary is the right button, whose press opens context menus.

ClickCount performs a click sequence of the given length (1 for a click, 2 for a double click, 3 for a triple click); each press and release carries its position in the sequence.

Clipboard is the driver's private clipboard, including text an application returns through ui.EventResult.ClipboardText.

ClipboardImage returns the PNG the driver's private clipboard holds, or nil. The slice is the driver's own; do not modify it.

Close detaches the driver from its Invalidator and releases its resources.

DoubleClick clicks twice at a point in quick succession: the second press and release carry a click count of 2.

Drop delivers a drag of files from the system: a hover (FileDropOver) at a point, its end (FileDropLeave), or the drop with its paths. It reports whether the hit under the point took the files.

Frame is the window's content area in screen coordinates: where Config.Origin or the last MoveWindow put it (the screen's corner when neither), at the window's current size.

HitTest returns the front-most enabled interaction target at a logical-pixel point. It applies the same focus-scope and blocking-region rules as pointer input without moving the pointer or repainting.

HoldsKeys reports whether the focused terminal asked for presses and releases (TextInput.KeyReleases), the case in which KeyDown and KeyUp deliver key events with their Release flag.

Key delivers a key press with its modifiers. While a text field is being edited the key goes where a native window would send it: Tab and Escape (and Enter in a single-line field) to the application, everything else to the text system as an editing command. A terminal gets every named key raw, as ui.KeyEvents.

KeyDown presses a key and keeps it down until KeyUp, as a person holding it would. Modifier keys (ui.KeyShiftLeft and the like) stay held for every pointer, scroll and key the driver delivers meanwhile, so Shift-click and Ctrl-click work. A focused terminal that asked for releases (HoldsKeys) gets the press as a KeyEvent: a named key by Key, a printable key by Text, which character names; any other focus gets the key as Key or Chord would deliver it, and KeyUp then does nothing.

KeyUp releases a key KeyDown pressed. A key that is not down is ignored.

LastOpenDirectoryRequest returns the most recent OpenDirectory options observed by driver.

LastOpenFilesRequest returns the most recent OpenFiles options observed by driver. The returned Filters slice is borrowed from the application call.

LastOpenedPath returns the most recent file passed to OpenPath while this driver was active. Like LastOpenedURL, driver-backed runs record the request and open nothing.

LastOpenedURL returns the most recent target passed to OpenURL while this driver was active. Driver-backed runs record the request without asking the operating system to open anything.

LastSaveFileRequest returns the most recent SaveFile options observed by driver. The returned Filters slice is borrowed from the application call.

Leave moves the pointer out of the window.

LoseFocus makes the window lose the keyboard, as switching to another application does: keys held down are released first. Modifiers held by KeyDown are forgotten with them.

Maximized reports the state SetMaximized last reported.

Minimized reports the state SetMinimized last reported.

Move moves the pointer to a point in logical pixels.

MoveWindow places the content area at a screen point, as dragging the window would, and reports the new frame to OnFrameChange.

NativeAppearance is what the application last asked SetNativeAppearance for, AppearanceUnknown (the system's own) if it has not.

Now is the driver's virtual time, which starts at zero.

Press presses a pointer button at a point (moving there first) as a lone click.

PressAt reports what a press at a point would do in a custom-titlebar window: whether the platform moves the window from there, now or once the pointer drags, or the application takes the press. It applies the same rules as the platform's own question, so a test can assert that a title bar moves the window and that a menu's backdrop over it still takes the press.

PressCount presses a button as the clicks-th press of a click sequence (2 for the second press of a double click), the way the operating system reports it.

Pump applies a pending background repaint request, the way a window would on its next loop turn: OnWake runs, then the application repaints. Every input method pumps first, so state published by another goroutine is visible to the event that follows.

QueueOpenDirectory queues the result returned by the next OpenDirectory call made while driver is active.

QueueOpenFiles queues the result returned by the next OpenFiles call made while driver is active. Paths are copied so the queued response does not depend on caller-owned slice storage.

QueueSaveFile queues the result returned by the next SaveFile call made while driver is active. It lets headless tools exercise native file-save workflows without opening an operating-system dialog.

Release releases a pointer button at a point, as the lone click's release.

ReleaseCount releases a button with the count of the press it ends.

Resize changes the content size in logical pixels and repaints.

Scroll delivers a scroll gesture at a logical-pixel window point. Positive deltas reveal content below and to the right. Target and Viewport are derived from the current frame; the other fields are delivered as supplied.

SelectText selects a rune range of the focused text field.

SetClipboard replaces the driver's private clipboard.

SetClipboardImage replaces the driver's private clipboard with a PNG image, as another application copying a picture would. The text it held is gone, as on a real clipboard. The bytes are copied. A nil or empty png empties the clipboard of images. The image must be a PNG within MaxClipboardImageBytes.

SetMaximized reports the window as maximized or restored, as the window manager would, and calls OnMaximize.

SetMinimized reports the window as minimized or restored, as the window manager would, and calls OnMinimize.

SetSystemAppearance changes what SystemAppearance reports while this driver runs and tells the watchers, as the system would.

Shortcut delivers a Command-key shortcut. It is retained as the compact editing helper; use ShortcutChord when the complete modifier set matters.

ShortcutChord handles ordinary text editing before offering other chords to the application and applying the terminal fallback. The complete modifier set is preserved, which lets headless tests exercise application shortcuts such as Command+Alt+X without bypassing the native text path.

Snapshot captures the current frame. The result is independent of later driver calls.

Transitioning reports whether a transition is in flight: the last paint asked for the next frame at display cadence. A display that changes slowly (a spinner stepping every 125 ms) asks later and does not count, so waiting for the application to come to rest ends even with one on screen.

Type inserts text into the focused text field, replacing its selection.

Wakes receives a value whenever a background goroutine asked for a repaint since the last Pump. Tools use it to sleep until there is something to apply.