src/frontend/Index.svelte

<!-- videoslider/frontend/Index.svelte -->
<svelte:options accessors={true} />

<script lang="ts">
	// Svelte and Gradio imports
	import { tick } from "svelte";
	import type { Gradio } from "@gradio/utils";
	import { Block } from "@gradio/atoms";
	import { StatusTracker } from "@gradio/statustracker";
	import type { FileData } from "@gradio/client";
	import type { LoadingStatus } from "@gradio/statustracker";
	
	// Local component imports
	import VideoSliderPreview from "./shared/VideoSliderPreview.svelte";
	import InteractiveVideoSlider from "./shared/InteractiveVideoSlider.svelte";

	// ------------------
	// Props from Backend
	// ------------------
	export let elem_id = "";
	export let elem_classes: string[] = [];
	export let visible = true;
	/** The core value of the component: a tuple of two video files. */
	export let value: [FileData | null, FileData | null] = [null, null];
	export let label: string;
	export let show_label: boolean;
	export let root: string;
	export let height: number | undefined;
	export let width: number | undefined;
	export let container = true;
	export let scale: number | null = null;
	export let min_width: number | undefined = undefined;
	export let loading_status: LoadingStatus;
	export let interactive: boolean;
	export let show_download_button: boolean;
	export let show_fullscreen_button: boolean;
	export let show_mute_button: boolean;
	/** Determines whether to show the upload interface or the preview player. */
	export let video_mode: "upload" | "preview" = "preview";
	/** The initial position of the slider, from 0 to 100. */
	export let position: number;
	export let autoplay: boolean;
	export let loop: boolean;
	/** The Gradio event dispatcher. */
	export let gradio: Gradio<{
		change: never;
		clear: never;
		upload: never;
		error: string;
	}>;

	// -----------------
	// Internal State
	// -----------------
	/** Holds the fullscreen state for the component. */
	let fullscreen = false;
	/** Stores the previous value to detect changes. */
	let old_value: [FileData | null, FileData | null] = [null, null];
	/** Tracks if the user is dragging over the upload area. */
	let dragging = false;

	// -----------------
	// Reactive Logic
	// -----------------

	/** Converts the 0-100 position from Python to a 0-1 scale for the child component. */
	$: normalised_slider_position = Math.max(0, Math.min(100, position)) / 100;

	/** Dispatches a 'change' event whenever the `value` prop is updated from within the component. */
	$: {
		if (JSON.stringify(value) !== JSON.stringify(old_value)) {
			old_value = value;
			gradio.dispatch("change");
		}
	}

	/**
	 * Handles the fullscreen event from the child component.
	 * It updates the internal state and resets the slider position to the center.
	 * @param detail The new fullscreen state (true or false).
	 */
	function handle_fullscreen_change(detail: boolean) {
		fullscreen = detail;
		position = 50; // Center the slider on fullscreen change
		tick().then(() => gradio.dispatch("change"));
	}
</script>

{#if video_mode=="preview"}
	<Block
		{visible}
		variant={"solid"}
		border_mode={dragging ? "focus" : "base"}
		padding={false}
		{elem_id}
		{elem_classes}
		{height}
		{width}
		{container}
		{scale}
		{min_width}
		allow_overflow={false}
		bind:fullscreen
	>
		<StatusTracker
			autoscroll={gradio.autoscroll}
			i18n={gradio.i18n}
			{...loading_status}
		/>
		<VideoSliderPreview
			bind:value
			{interactive}
            {fullscreen}
			{label}
			{show_label}
			{show_download_button}
			{show_fullscreen_button}
			{show_mute_button}
			i18n={gradio.i18n}
			bind:position={normalised_slider_position}
			slider_color="var(--border-color-primary)"
			on:clear={() => gradio.dispatch("clear")}
			on:fullscreen={({ detail }) => handle_fullscreen_change(detail)}
			{autoplay}
			{loop}
			upload={(...args) => gradio.client.upload(...args)}
		/>
	</Block>
{:else}
	<Block
		{visible}
		variant={"solid"}
		border_mode={dragging ? "focus" : "base"}
		padding={true}
		{elem_id}
		{elem_classes}
		{height}
		{width}
		{container}
		{scale}
		{min_width}
		allow_overflow={false}
	>
		<StatusTracker
			autoscroll={gradio.autoscroll}
			i18n={gradio.i18n}
			{...loading_status}
		/>
		<InteractiveVideoSlider
			bind:value
			{root}
			on:upload={() => gradio.dispatch("upload")}
			on:clear={() => gradio.dispatch("clear")}
			on:error={({ detail }) => gradio.dispatch("error", detail)}
			{label}
			{show_label}
			max_file_size={gradio.max_file_size}
			i18n={gradio.i18n}
			upload={(...args) => gradio.client.upload(...args)}
			stream_handler={gradio.client?.stream}
			{autoplay}
			{loop}
		/>
	</Block>
{/if}