Files
dees-catalog/ts_web/elements/dees-pdf-preview/component.ts

448 lines
12 KiB
TypeScript

import { DeesElement, property, html, customElement, domtools, type TemplateResult, css, cssManager } from '@design.estate/dees-element';
import { PdfManager } from '../dees-pdf-shared/PdfManager.js';
import { CanvasPool, type PooledCanvas } from '../dees-pdf-shared/CanvasPool.js';
import { PerformanceMonitor, throttle } from '../dees-pdf-shared/utils.js';
import { previewStyles } from './styles.js';
import { demo as demoFunc } from './demo.js';
import { DeesContextmenu } from '../dees-contextmenu.js';
import '../dees-icon.js';
declare global {
interface HTMLElementTagNameMap {
'dees-pdf-preview': DeesPdfPreview;
}
}
@customElement('dees-pdf-preview')
export class DeesPdfPreview extends DeesElement {
public static demo = demoFunc;
public static styles = previewStyles;
@property({ type: String })
public pdfUrl: string = '';
@property({ type: Number })
public maxPages: number = 3;
@property({ type: Number })
public stackOffset: number = 8;
@property({ type: Boolean })
public clickable: boolean = true;
@property({ type: Number })
private pageCount: number = 0;
@property({ type: Boolean })
private loading: boolean = false;
@property({ type: Boolean })
private rendered: boolean = false;
@property({ type: Boolean })
private error: boolean = false;
private renderPagesTask: Promise<void> | null = null;
private renderPagesQueued: boolean = false;
private observer: IntersectionObserver;
private pdfDocument: any;
private canvases: PooledCanvas[] = [];
private resizeObserver?: ResizeObserver;
private previewContainer: HTMLElement | null = null;
private stackElement: HTMLElement | null = null;
private loadedPdfUrl: string | null = null;
constructor() {
super();
}
public render(): TemplateResult {
return html`
<div
class="preview-container ${this.loading ? 'loading' : ''} ${this.error ? 'error' : ''} ${this.clickable ? 'clickable' : ''}"
@click=${this.handleClick}
>
${this.loading ? html`
<div class="preview-loading">
<div class="preview-spinner"></div>
<div class="preview-text">Loading preview...</div>
</div>
` : ''}
${this.error ? html`
<div class="preview-error">
<dees-icon icon="lucide:FileX"></dees-icon>
<div class="preview-text">Failed to load PDF</div>
</div>
` : ''}
${!this.loading && !this.error ? html`
<div class="preview-stack">
${this.getStackedCanvases()}
</div>
${this.pageCount > 0 ? html`
<div class="preview-info">
<dees-icon icon="lucide:FileText"></dees-icon>
<span class="preview-pages">${this.pageCount} page${this.pageCount > 1 ? 's' : ''}</span>
</div>
` : ''}
${this.clickable ? html`
<div class="preview-overlay">
<dees-icon icon="lucide:Eye"></dees-icon>
<span>View PDF</span>
</div>
` : ''}
` : ''}
</div>
`;
}
private getStackedCanvases(): TemplateResult[] {
const pagesToShow = Math.min(this.pageCount, this.maxPages);
const canvases: TemplateResult[] = [];
for (let i = pagesToShow - 1; i >= 0; i--) {
const offset = i * this.stackOffset;
canvases.push(html`
<canvas
class="preview-canvas"
data-page="${i + 1}"
style="
top: ${offset}px;
left: ${offset}px;
z-index: ${pagesToShow - i};
${i > 0 ? `box-shadow: 0 2px 8px rgba(0, 0, 0, ${0.1 + (i * 0.05)});` : ''}
"
></canvas>
`);
}
return canvases;
}
public async connectedCallback() {
await super.connectedCallback();
this.setupIntersectionObserver();
await this.updateComplete;
this.cacheElements();
this.setupResizeObserver();
}
public async disconnectedCallback() {
await super.disconnectedCallback();
this.cleanup();
if (this.observer) {
this.observer.disconnect();
}
this.resizeObserver?.disconnect();
this.resizeObserver = undefined;
}
private setupIntersectionObserver() {
const options = {
root: null,
rootMargin: '200px',
threshold: 0.01,
};
this.observer = new IntersectionObserver(
throttle((entries) => {
for (const entry of entries) {
if (entry.isIntersecting && !this.rendered && this.pdfUrl) {
this.loadAndRenderPreview();
} else if (!entry.isIntersecting && this.rendered) {
// Optional: Clear canvases when out of view for memory optimization
// this.clearCanvases();
}
}
}, 100),
options
);
this.observer.observe(this);
}
private async loadAndRenderPreview() {
if (this.rendered || this.loading) return;
this.loading = true;
this.error = false;
PerformanceMonitor.mark(`preview-load-${this.pdfUrl}`);
try {
this.pdfDocument = await PdfManager.loadDocument(this.pdfUrl);
this.pageCount = this.pdfDocument.numPages;
this.loadedPdfUrl = this.pdfUrl;
await this.updateComplete;
this.cacheElements();
await this.scheduleRenderPages();
this.rendered = true;
const duration = PerformanceMonitor.measure(`preview-render-${this.pdfUrl}`, `preview-load-${this.pdfUrl}`);
console.log(`PDF preview rendered in ${duration}ms`);
} catch (error) {
console.error('Failed to load PDF preview:', error);
this.error = true;
} finally {
this.loading = false;
}
}
private scheduleRenderPages(): Promise<void> {
if (!this.pdfDocument) {
return Promise.resolve();
}
if (this.renderPagesTask) {
this.renderPagesQueued = true;
return this.renderPagesTask;
}
this.renderPagesTask = (async () => {
try {
await this.performRenderPages();
} catch (error) {
console.error('Failed to render PDF preview pages:', error);
}
})().finally(() => {
this.renderPagesTask = null;
if (this.renderPagesQueued) {
this.renderPagesQueued = false;
void this.scheduleRenderPages();
}
});
return this.renderPagesTask;
}
private async performRenderPages() {
if (!this.pdfDocument) return;
const canvasElements = this.shadowRoot?.querySelectorAll('.preview-canvas') as NodeListOf<HTMLCanvasElement>;
const pagesToRender = Math.min(this.pageCount, this.maxPages);
// Release old canvases
this.clearCanvases();
const maxStackOffset = (pagesToRender - 1) * this.stackOffset;
this.cacheElements();
const { availableWidth, availableHeight } = this.getAvailableStackSize(maxStackOffset);
// Render pages in reverse order (back to front for stacking)
for (let i = 0; i < pagesToRender; i++) {
const canvas = canvasElements[i];
if (!canvas) continue;
const pageNum = parseInt(canvas.dataset.page || '1');
const page = await this.pdfDocument.getPage(pageNum);
// Calculate scale to fit within available area while keeping aspect ratio
const initialViewport = page.getViewport({ scale: 1 });
const scaleX = availableWidth > 0 ? availableWidth / initialViewport.width : 0;
const scaleY = availableHeight > 0 ? availableHeight / initialViewport.height : 0;
const scale = Math.min(scaleX || 0.5, scaleY || scaleX || 0.5, 0.75);
if (!Number.isFinite(scale) || scale <= 0) {
page.cleanup?.();
continue;
}
const viewport = page.getViewport({ scale });
// Acquire canvas from pool
const pooledCanvas = CanvasPool.acquire(viewport.width, viewport.height);
this.canvases.push(pooledCanvas);
// Render to pooled canvas first
const renderContext = {
canvasContext: pooledCanvas.ctx,
viewport: viewport,
};
await page.render(renderContext).promise;
// Transfer to display canvas
canvas.width = viewport.width;
canvas.height = viewport.height;
canvas.style.width = `${viewport.width}px`;
canvas.style.height = `${viewport.height}px`;
const ctx = canvas.getContext('2d');
if (ctx) {
ctx.drawImage(pooledCanvas.canvas, 0, 0);
}
// Release page to free memory
page.cleanup();
}
}
private clearCanvases() {
// Release pooled canvases
for (const pooledCanvas of this.canvases) {
CanvasPool.release(pooledCanvas);
}
this.canvases = [];
}
private cleanup() {
this.clearCanvases();
if (this.pdfDocument) {
PdfManager.releaseDocument(this.loadedPdfUrl ?? this.pdfUrl);
this.pdfDocument = null;
}
this.renderPagesQueued = false;
this.pageCount = 0;
this.previewContainer = null;
this.stackElement = null;
this.loadedPdfUrl = null;
this.rendered = false;
this.loading = false;
this.error = false;
}
private handleClick() {
if (!this.clickable) return;
// Dispatch custom event for parent to handle
this.dispatchEvent(new CustomEvent('pdf-preview-click', {
detail: {
pdfUrl: this.pdfUrl,
pageCount: this.pageCount,
},
bubbles: true,
composed: true,
}));
}
public async updated(changedProperties: Map<PropertyKey, unknown>) {
super.updated(changedProperties);
if (changedProperties.has('pdfUrl') && this.pdfUrl) {
const previousUrl = changedProperties.get('pdfUrl') as string | undefined;
if (previousUrl) {
PdfManager.releaseDocument(previousUrl);
}
this.cleanup();
this.rendered = false;
// Check if in viewport and render if so
if (this.observer) {
const rect = this.getBoundingClientRect();
if (rect.top < window.innerHeight && rect.bottom > 0) {
this.loadAndRenderPreview();
}
}
}
if ((changedProperties.has('maxPages') || changedProperties.has('stackOffset')) && this.rendered) {
await this.scheduleRenderPages();
}
}
/**
* Provide context menu items for right-click functionality
*/
public getContextMenuItems() {
const items: any[] = [];
// If clickable, add option to view the PDF
if (this.clickable) {
items.push({
name: 'View PDF',
iconName: 'lucide:Eye',
action: async () => {
this.handleClick();
}
});
items.push({ divider: true });
}
items.push(
{
name: 'Open PDF in New Tab',
iconName: 'lucide:ExternalLink',
action: async () => {
window.open(this.pdfUrl, '_blank');
}
},
{ divider: true },
{
name: 'Copy PDF URL',
iconName: 'lucide:Copy',
action: async () => {
await navigator.clipboard.writeText(this.pdfUrl);
}
},
{
name: 'Download PDF',
iconName: 'lucide:Download',
action: async () => {
const link = document.createElement('a');
link.href = this.pdfUrl;
link.download = this.pdfUrl.split('/').pop() || 'document.pdf';
link.click();
}
}
);
// Add page count info as a disabled item
if (this.pageCount > 0) {
items.push(
{ divider: true },
{
name: `${this.pageCount} page${this.pageCount > 1 ? 's' : ''}`,
iconName: 'lucide:FileText',
disabled: true,
action: async () => {}
}
);
}
return items;
}
private cacheElements() {
if (!this.previewContainer) {
this.previewContainer = this.shadowRoot?.querySelector('.preview-container') as HTMLElement;
}
if (!this.stackElement) {
this.stackElement = this.shadowRoot?.querySelector('.preview-stack') as HTMLElement;
}
}
private setupResizeObserver() {
if (!this.previewContainer || this.resizeObserver) return;
this.resizeObserver = new ResizeObserver(() => {
if (this.rendered && this.pdfDocument && !this.loading) {
void this.scheduleRenderPages();
}
});
this.resizeObserver.observe(this);
}
private getAvailableStackSize(maxStackOffset: number) {
if (!this.stackElement) {
return {
availableWidth: 0,
availableHeight: 0,
};
}
const rect = this.stackElement.getBoundingClientRect();
const availableWidth = Math.max(rect.width - maxStackOffset, 0);
const availableHeight = Math.max(rect.height - maxStackOffset, 0);
return { availableWidth, availableHeight };
}
}