InteractiveViewer

Examples#

Handling events#

import flet as ft


def main(page: ft.Page):
    page.add(
        ft.InteractiveViewer(
            min_scale=0.1,
            max_scale=15,
            boundary_margin=ft.margin.all(20),
            on_interaction_start=lambda e: print(e),
            on_interaction_end=lambda e: print(e),
            on_interaction_update=lambda e: print(e),
            content=ft.Image(
                src="https://picsum.photos/500/500",
            ),
        )
    )


ft.run(main)

InteractiveViewer #

Bases: LayoutControl

Allows you to pan, zoom, and rotate its content.

RAISES	DESCRIPTION
`AssertionError`	If `content` is not visible.
`AssertionError`	If `min_scale` is not greater than `0`.
`AssertionError`	If `max_scale` is not greater than `0`.
`AssertionError`	If `max_scale` is less than `min_scale`.
`AssertionError`	If `interaction_end_friction_coefficient` is not greater than `0`.

alignment #

alignment: Alignment | None = None

Alignment of the content within.

boundary_margin #

boundary_margin: MarginValue = 0

A margin for the visible boundaries of the content.

clip_behavior #

clip_behavior: ClipBehavior = HARD_EDGE

How to clip the content.

constrained #

constrained: bool = True

Whether the normal size constraints at this point in the widget tree are applied to the child.

content #

content: Control

The Control to be transformed.

interaction_end_friction_coefficient #

interaction_end_friction_coefficient: Number = 1.35e-05

Changes the deceleration behavior after a gesture.

Note

Must be greater than 0.

interaction_update_interval #

interaction_update_interval: int = 200

The interval (in milliseconds) at which the on_interaction_update event is fired.

max_scale #

max_scale: Number = 2.5

The maximum allowed scale.

Note

Must be greater than or equal to min_scale.

min_scale #

min_scale: Number = 0.8

The minimum allowed scale.

Note

Must be greater than 0 and less than or equal to max_scale.

on_interaction_end #

on_interaction_end: (
    EventHandler[ScaleEndEvent[InteractiveViewer]] | None
) = None

Called when the user ends a pan or scale gesture.

on_interaction_start #

on_interaction_start: (
    EventHandler[ScaleStartEvent[InteractiveViewer]] | None
) = None

Called when the user begins a pan or scale gesture.

on_interaction_update #

on_interaction_update: (
    EventHandler[ScaleUpdateEvent[InteractiveViewer]] | None
) = None

Called when the user updates a pan or scale gesture.

pan_enabled #

pan_enabled: bool = True

Whether panning is enabled.

scale_enabled #

scale_enabled: bool = True

Whether scaling is enabled.

scale_factor #

scale_factor: Number = 200

The amount of scale to be performed per pointer scroll.

trackpad_scroll_causes_scale #

trackpad_scroll_causes_scale: bool = False

Whether scrolling up/down on a trackpad should cause scaling instead of panning.

before_update #

before_update()

pan #

pan(dx: Number, dy: Number = 0, dz: Number = 0)

reset #

reset(animation_duration: DurationValue | None = None)

restore_state #

restore_state()

save_state #

save_state()

zoom #

zoom(factor: Number)