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<template>
<div :class="[$style.root, { [$style.cover]: cover }]" :title="title ?? ''">
<canvas v-if="!loaded || forceBlurhash" ref="canvas" :class="$style.canvas" :width="width" :height="height" :title="title ?? ''"/>
<img v-if="src && !forceBlurhash" v-show="loaded" :class="$style.img" :src="src" :title="title ?? ''" :alt="alt ?? ''" @load="onLoad"/>
</div>
</template>
<script lang="ts" setup>
import { onMounted, watch } from 'vue';
import { decode } from 'blurhash';
const props = withDefaults(defineProps<{
src?: string | null;
hash?: string;
alt?: string | null;
title?: string | null;
height?: number;
width?: number;
cover?: boolean;
forceBlurhash?: boolean;
}>(), {
src: null,
alt: '',
title: null,
height: 64,
width: 64,
cover: true,
forceBlurhash: false,
});
const canvas = $shallowRef<HTMLCanvasElement>();
let loaded = $ref(false);
let width = $ref(props.width);
let height = $ref(props.height);
function onLoad() {
loaded = true;
}
watch([() => props.width, () => props.height], () => {
const ratio = props.width / props.height;
if (ratio > 1) {
width = Math.round(64 * ratio);
height = 64;
} else {
width = 64;
height = Math.round(64 / ratio);
}
}, {
immediate: true,
});
function draw() {
if (props.hash == null) return;
const pixels = decode(props.hash, width, height);
const ctx = canvas.getContext('2d');
const imageData = ctx!.createImageData(width, height);
imageData.data.set(pixels);
ctx!.putImageData(imageData, 0, 0);
}
watch(() => props.hash, () => {
draw();
});
onMounted(() => {
draw();
});
</script>
<style lang="scss" module>
.root {
position: relative;
width: 100%;
height: 100%;
&.cover {
> .canvas,
> .img {
object-fit: cover;
}
}
}
.canvas,
.img {
display: block;
width: 100%;
height: 100%;
}
.canvas {
object-fit: contain;
}
.img {
object-fit: contain;
}
</style>
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