feat(modal): add zoomable image viewer

src/app/core/services/modal.service.ts

@@ -2,16 +2,19 @@ import { InjectionToken, Injectable, Type, signal } from '@angular/core';
 import { Observable, Subject, map } from 'rxjs';
 import { ConfirmDeleteModalComponent } from '../../shared/components/confirm-delete-modal/confirm-delete-modal.component';
 import { ConfirmModalComponent } from '../../shared/components/confirm-modal/confirm-modal.component';
+import { ImageModalComponent } from '../../shared/components/image-modal/image-modal.component';
 import { QrModalComponent } from '../../shared/components/qr-modal/qr-modal.component';
 import { SimpleModalComponent } from '../../shared/components/simple-modal/simple-modal.component';
 
 export type ModalSize = 'qr' | 'sm' | 'md' | 'lg' | 'xl' | 'full';
 export type ModalDismissReason = 'backdrop' | 'escape' | 'programmatic' | 'replaced';
+export type ModalPresentation = 'dialog' | 'fullscreen-media';
 
 export interface ModalConfig<TData = unknown> {
   title?: string;
   data?: TData;
   size?: ModalSize;
+  presentation?: ModalPresentation;
   closeOnBackdrop?: boolean;
   closeOnEscape?: boolean;
   showCloseButton?: boolean;
@@ -62,6 +65,25 @@ export interface QrModalConfig extends Omit<ModalConfig<QrModalData>, 'data' | '
   ticket: string;
 }
 
+export interface ImageModalData {
+  src: string;
+  alt: string;
+  initialZoom: number;
+  minZoom: number;
+  maxZoom: number;
+}
+
+export interface ImageModalConfig extends Omit<
+  ModalConfig<ImageModalData>,
+  'data' | 'presentation' | 'size'
+> {
+  src: string;
+  alt: string;
+  initialZoom?: number;
+  minZoom?: number;
+  maxZoom?: number;
+}
+
 export interface ActiveModalState<TResult = unknown, TData = unknown> {
   component: Type<unknown>;
   config: NormalizedModalConfig<TData>;
@@ -195,6 +217,33 @@ export class ModalService {
     });
   }
 
+  openImage(config: ImageModalConfig): Observable<void> {
+    return this.openImageRef(config).afterClosed$.pipe(map(() => undefined));
+  }
+
+  openImageRef(config: ImageModalConfig): ModalRef<void> {
+    const { src, alt, initialZoom = 1, minZoom = 1, maxZoom = 4, ...modalConfig } = config;
+    const normalizedMinZoom = Math.max(0.1, minZoom);
+    const normalizedMaxZoom = Math.max(normalizedMinZoom, maxZoom);
+    const normalizedInitialZoom = Math.min(
+      normalizedMaxZoom,
+      Math.max(normalizedMinZoom, initialZoom),
+    );
+
+    return this.open(ImageModalComponent, {
+      ...modalConfig,
+      size: 'full',
+      presentation: 'fullscreen-media',
+      data: {
+        src,
+        alt,
+        initialZoom: normalizedInitialZoom,
+        minZoom: normalizedMinZoom,
+        maxZoom: normalizedMaxZoom,
+      },
+    });
+  }
+
   private close<TResult>(ref: ModalRef<TResult>, result?: TResult): void {
     if (this.activeModalState()?.ref !== ref) {
       return;

src/app/shared/components/image-modal/image-modal.component.html

@@ -0,0 +1,52 @@
+<div class="image-modal">
+  <div
+    #viewport
+    class="image-modal__viewport"
+    [class.image-modal__viewport--zoomed]="zoom() > data.minZoom"
+    (wheel)="onWheel($event)"
+    (dblclick)="onDoubleClick($event)"
+    (pointerdown)="onPointerDown($event)"
+    (pointermove)="onPointerMove($event)"
+    (pointerup)="onPointerUp($event)"
+    (pointercancel)="onPointerUp($event)"
+  >
+    @if (!imageFailed()) {
+      <img
+        #image
+        class="image-modal__image"
+        [src]="data.src"
+        [alt]="data.alt"
+        [style.transform]="transform()"
+        draggable="false"
+        (load)="onImageLoad()"
+        (error)="imageFailed.set(true)"
+      />
+    } @else {
+      <p class="image-modal__error" role="alert">No se pudo cargar la imagen.</p>
+    }
+  </div>
+
+  <div class="image-modal__controls" aria-label="Controles de zoom">
+    <button
+      type="button"
+      class="image-modal__control"
+      aria-label="Alejar"
+      [disabled]="zoom() <= data.minZoom"
+      (click)="zoomOut()"
+    >
+      &minus;
+    </button>
+    <button type="button" class="image-modal__zoom" aria-label="Restablecer zoom" (click)="reset()">
+      {{ zoomLabel() }}
+    </button>
+    <button
+      type="button"
+      class="image-modal__control"
+      aria-label="Acercar"
+      [disabled]="zoom() >= data.maxZoom"
+      (click)="zoomIn()"
+    >
+      &plus;
+    </button>
+  </div>
+</div>

src/app/shared/components/image-modal/image-modal.component.scss

@@ -0,0 +1,124 @@
+:host {
+  display: flex;
+  min-height: 0;
+  flex: 1;
+}
+
+.image-modal {
+  position: relative;
+  display: flex;
+  min-width: 0;
+  min-height: 0;
+  flex: 1;
+  flex-direction: column;
+  overflow: hidden;
+  background: #111111;
+}
+
+.image-modal__viewport {
+  display: flex;
+  min-width: 0;
+  min-height: 0;
+  flex: 1;
+  align-items: center;
+  justify-content: center;
+  overflow: hidden;
+  cursor: zoom-in;
+  touch-action: none;
+  user-select: none;
+}
+
+.image-modal__viewport--zoomed {
+  cursor: grab;
+}
+
+.image-modal__viewport--zoomed:active {
+  cursor: grabbing;
+}
+
+.image-modal__image {
+  display: block;
+  max-width: 100%;
+  max-height: 100%;
+  object-fit: contain;
+  transform-origin: center;
+  transition: transform 120ms ease-out;
+  will-change: transform;
+  -webkit-user-drag: none;
+}
+
+.image-modal__viewport:active .image-modal__image {
+  transition: none;
+}
+
+.image-modal__error {
+  margin: 1rem;
+  color: #ffffff;
+  text-align: center;
+}
+
+.image-modal__controls {
+  position: absolute;
+  right: 50%;
+  bottom: max(1.25rem, env(safe-area-inset-bottom));
+  z-index: 1;
+  display: flex;
+  align-items: center;
+  overflow: hidden;
+  border: 1px solid rgba(255, 255, 255, 0.25);
+  border-radius: 2rem;
+  background: rgba(20, 20, 20, 0.78);
+  box-shadow: 0 0.25rem 1rem rgba(0, 0, 0, 0.3);
+  transform: translateX(50%);
+  backdrop-filter: blur(0.5rem);
+}
+
+.image-modal__control,
+.image-modal__zoom {
+  display: inline-flex;
+  height: 2.75rem;
+  align-items: center;
+  justify-content: center;
+  border: 0;
+  color: #ffffff;
+  background: transparent;
+}
+
+.image-modal__control {
+  width: 2.75rem;
+  font-size: 1.5rem;
+}
+
+.image-modal__zoom {
+  min-width: 4rem;
+  padding: 0 0.5rem;
+  font-size: 0.875rem;
+  font-variant-numeric: tabular-nums;
+}
+
+.image-modal__control:hover:not(:disabled),
+.image-modal__zoom:hover {
+  background: rgba(255, 255, 255, 0.12);
+}
+
+.image-modal__control:focus-visible,
+.image-modal__zoom:focus-visible {
+  outline: 2px solid #ffffff;
+  outline-offset: -3px;
+}
+
+.image-modal__control:disabled {
+  opacity: 0.35;
+}
+
+@media (max-width: 576px) {
+  .image-modal__controls {
+    bottom: max(1rem, env(safe-area-inset-bottom));
+  }
+}
+
+@media (prefers-reduced-motion: reduce) {
+  .image-modal__image {
+    transition: none;
+  }
+}

src/app/shared/components/image-modal/image-modal.component.ts

@@ -0,0 +1,231 @@
+import {
+  ChangeDetectionStrategy,
+  Component,
+  ElementRef,
+  computed,
+  inject,
+  signal,
+  viewChild,
+} from '@angular/core';
+
+import { ImageModalData, MODAL_DATA } from '../../../core/services/modal.service';
+
+interface Point {
+  x: number;
+  y: number;
+}
+
+@Component({
+  selector: 'app-image-modal',
+  templateUrl: './image-modal.component.html',
+  styleUrl: './image-modal.component.scss',
+  changeDetection: ChangeDetectionStrategy.OnPush,
+})
+export class ImageModalComponent {
+  protected readonly data = inject<ImageModalData>(MODAL_DATA);
+  private readonly viewport = viewChild.required<ElementRef<HTMLElement>>('viewport');
+  private readonly image = viewChild<ElementRef<HTMLImageElement>>('image');
+  private readonly pointers = new Map<number, Point>();
+
+  protected readonly zoom = signal(this.data.initialZoom);
+  protected readonly offsetX = signal(0);
+  protected readonly offsetY = signal(0);
+  protected readonly imageFailed = signal(false);
+  protected readonly transform = computed(
+    () => `translate3d(${this.offsetX()}px, ${this.offsetY()}px, 0) scale(${this.zoom()})`,
+  );
+  protected readonly zoomLabel = computed(() => `${Math.round(this.zoom() * 100)}%`);
+
+  private dragStart: Point | null = null;
+  private dragOffset: Point = { x: 0, y: 0 };
+  private pinchDistance = 0;
+  private pinchZoom = 1;
+  private pinchLocal: Point = { x: 0, y: 0 };
+  private pointerDownAt: Point | null = null;
+  private gestureMoved = false;
+  private hadMultiplePointers = false;
+  private lastTapAt = 0;
+
+  protected zoomIn(): void {
+    this.setZoomAt(Math.min(this.data.maxZoom, this.zoom() + 0.5));
+  }
+
+  protected zoomOut(): void {
+    this.setZoomAt(Math.max(this.data.minZoom, this.zoom() - 0.5));
+  }
+
+  protected reset(): void {
+    this.zoom.set(this.data.initialZoom);
+    this.offsetX.set(0);
+    this.offsetY.set(0);
+  }
+
+  protected onWheel(event: WheelEvent): void {
+    event.preventDefault();
+    const factor = event.deltaY < 0 ? 1.15 : 1 / 1.15;
+    this.setZoomAt(this.zoom() * factor, event.clientX, event.clientY);
+  }
+
+  protected onDoubleClick(event: MouseEvent): void {
+    this.toggleZoom(event.clientX, event.clientY);
+  }
+
+  protected onPointerDown(event: PointerEvent): void {
+    if (event.pointerType === 'mouse' && event.button !== 0) {
+      return;
+    }
+
+    event.preventDefault();
+    this.viewport().nativeElement.setPointerCapture?.(event.pointerId);
+    const point = { x: event.clientX, y: event.clientY };
+    this.pointers.set(event.pointerId, point);
+    this.pointerDownAt = point;
+    this.gestureMoved = false;
+
+    if (this.pointers.size === 1) {
+      this.dragStart = point;
+      this.dragOffset = { x: this.offsetX(), y: this.offsetY() };
+    } else if (this.pointers.size === 2) {
+      this.hadMultiplePointers = true;
+      this.beginPinch();
+    }
+  }
+
+  protected onPointerMove(event: PointerEvent): void {
+    if (!this.pointers.has(event.pointerId)) {
+      return;
+    }
+
+    const point = { x: event.clientX, y: event.clientY };
+    this.pointers.set(event.pointerId, point);
+
+    if (this.pointerDownAt && this.distance(this.pointerDownAt, point) > 4) {
+      this.gestureMoved = true;
+    }
+
+    if (this.pointers.size === 2) {
+      const [first, second] = [...this.pointers.values()];
+      const distance = this.distance(first, second);
+      const midpoint = this.midpoint(first, second);
+      const nextZoom = this.clampZoom(this.pinchZoom * (distance / this.pinchDistance));
+      const rect = this.viewport().nativeElement.getBoundingClientRect();
+
+      this.zoom.set(nextZoom);
+      this.offsetX.set(midpoint.x - (rect.left + rect.width / 2) - this.pinchLocal.x * nextZoom);
+      this.offsetY.set(midpoint.y - (rect.top + rect.height / 2) - this.pinchLocal.y * nextZoom);
+      this.clampOffset();
+      return;
+    }
+
+    if (this.pointers.size === 1 && this.dragStart && this.zoom() > this.data.minZoom) {
+      this.offsetX.set(this.dragOffset.x + point.x - this.dragStart.x);
+      this.offsetY.set(this.dragOffset.y + point.y - this.dragStart.y);
+      this.clampOffset();
+    }
+  }
+
+  protected onPointerUp(event: PointerEvent): void {
+    const wasTouch = event.pointerType === 'touch';
+    const tapPoint = this.pointers.get(event.pointerId);
+    this.pointers.delete(event.pointerId);
+    const viewport = this.viewport().nativeElement;
+    if (viewport.hasPointerCapture?.(event.pointerId)) {
+      viewport.releasePointerCapture(event.pointerId);
+    }
+
+    if (wasTouch && tapPoint && !this.gestureMoved && !this.hadMultiplePointers) {
+      const now = Date.now();
+      if (now - this.lastTapAt < 300) {
+        this.toggleZoom(tapPoint.x, tapPoint.y);
+        this.lastTapAt = 0;
+      } else {
+        this.lastTapAt = now;
+      }
+    }
+
+    if (this.pointers.size === 1) {
+      const remaining = [...this.pointers.values()][0];
+      this.dragStart = remaining;
+      this.dragOffset = { x: this.offsetX(), y: this.offsetY() };
+    } else if (this.pointers.size === 0) {
+      this.dragStart = null;
+      this.pointerDownAt = null;
+      this.hadMultiplePointers = false;
+      this.clampOffset();
+    }
+  }
+
+  protected onImageLoad(): void {
+    this.imageFailed.set(false);
+    this.clampOffset();
+  }
+
+  private beginPinch(): void {
+    const [first, second] = [...this.pointers.values()];
+    const midpoint = this.midpoint(first, second);
+    const rect = this.viewport().nativeElement.getBoundingClientRect();
+
+    this.pinchDistance = Math.max(1, this.distance(first, second));
+    this.pinchZoom = this.zoom();
+    this.pinchLocal = {
+      x: (midpoint.x - (rect.left + rect.width / 2) - this.offsetX()) / this.zoom(),
+      y: (midpoint.y - (rect.top + rect.height / 2) - this.offsetY()) / this.zoom(),
+    };
+  }
+
+  private toggleZoom(clientX?: number, clientY?: number): void {
+    const target =
+      this.zoom() > this.data.minZoom + 0.01
+        ? this.data.minZoom
+        : Math.min(this.data.maxZoom, Math.max(2, this.data.minZoom));
+    this.setZoomAt(target, clientX, clientY);
+  }
+
+  private setZoomAt(value: number, clientX?: number, clientY?: number): void {
+    const nextZoom = this.clampZoom(value);
+    const currentZoom = this.zoom();
+
+    if (clientX !== undefined && clientY !== undefined && currentZoom > 0) {
+      const rect = this.viewport().nativeElement.getBoundingClientRect();
+      const pointX = clientX - (rect.left + rect.width / 2);
+      const pointY = clientY - (rect.top + rect.height / 2);
+      const localX = (pointX - this.offsetX()) / currentZoom;
+      const localY = (pointY - this.offsetY()) / currentZoom;
+      this.offsetX.set(pointX - localX * nextZoom);
+      this.offsetY.set(pointY - localY * nextZoom);
+    }
+
+    this.zoom.set(nextZoom);
+    if (nextZoom <= this.data.minZoom) {
+      this.offsetX.set(0);
+      this.offsetY.set(0);
+    }
+    this.clampOffset();
+  }
+
+  private clampZoom(value: number): number {
+    return Math.min(this.data.maxZoom, Math.max(this.data.minZoom, value));
+  }
+
+  private clampOffset(): void {
+    const viewport = this.viewport().nativeElement;
+    const image = this.image()?.nativeElement;
+    if (!image) {
+      return;
+    }
+
+    const maxX = Math.max(0, (image.offsetWidth * this.zoom() - viewport.clientWidth) / 2);
+    const maxY = Math.max(0, (image.offsetHeight * this.zoom() - viewport.clientHeight) / 2);
+
+    this.offsetX.set(Math.min(maxX, Math.max(-maxX, this.offsetX())));
+    this.offsetY.set(Math.min(maxY, Math.max(-maxY, this.offsetY())));
+  }
+
+  private midpoint(first: Point, second: Point): Point {
+    return { x: (first.x + second.x) / 2, y: (first.y + second.y) / 2 };
+  }
+
+  private distance(first: Point, second: Point): number {
+    return Math.hypot(second.x - first.x, second.y - first.y);
+  }
+}

src/app/shared/components/modal-host/modal-host.component.html

@@ -2,6 +2,7 @@
   <app-modal-shell
     [title]="modal.config.title"
     [size]="modal.config.size"
+    [presentation]="modal.config.presentation ?? 'dialog'"
     [showCloseButton]="modal.config.showCloseButton"
     (backdropClick)="onBackdropClick()"
     (closeRequested)="onCloseRequested()"

src/app/shared/components/modal-shell/modal-shell.component.html

@@ -1,4 +1,8 @@
-<div class="modal-shell" (click)="backdropClick.emit()">
+<div
+  class="modal-shell"
+  [class.modal-shell--fullscreen-media]="presentation() === 'fullscreen-media'"
+  (click)="backdropClick.emit()"
+>
   <div
     class="modal-dialog modal-dialog-centered modal-dialog-scrollable modal-shell__dialog"
     [ngClass]="dialogClass()"

src/app/shared/components/modal-shell/modal-shell.component.scss

@@ -109,6 +109,64 @@
   color: #303030;
 }
 
+.modal-shell--fullscreen-media {
+  padding: 1.5rem;
+  background: rgba(0, 0, 0, 0.92);
+}
+
+.modal-shell--fullscreen-media .modal-shell__dialog {
+  width: 100%;
+  max-width: 100%;
+  height: calc(100dvh - 3rem);
+}
+
+.modal-shell--fullscreen-media .modal-shell__content {
+  min-height: 0;
+  height: 100%;
+  max-height: none;
+  overflow: hidden;
+  border-radius: 0.4rem;
+  background: #111111;
+}
+
+.modal-shell--fullscreen-media .modal-shell__header {
+  position: absolute;
+  inset: 0 0 auto;
+  z-index: 2;
+  justify-content: flex-start;
+  height: 0;
+  padding: 0;
+}
+
+.modal-shell--fullscreen-media .modal-shell__title {
+  position: absolute;
+  top: max(1.25rem, env(safe-area-inset-top));
+  left: max(1.25rem, env(safe-area-inset-left));
+  width: auto;
+  max-width: calc(100% - 8rem);
+  overflow: hidden;
+  color: #ffffff;
+  font-size: 1rem;
+  line-height: 1.4;
+  text-align: left;
+  text-overflow: ellipsis;
+  text-shadow: 0 1px 3px #000000;
+  white-space: nowrap;
+}
+
+.modal-shell--fullscreen-media .modal-shell__header .btn-close {
+  top: max(1rem, env(safe-area-inset-top));
+  right: max(1rem, env(safe-area-inset-right));
+  filter: invert(1) grayscale(1) brightness(2) drop-shadow(0 1px 2px #000000);
+}
+
+.modal-shell--fullscreen-media .modal-shell__body {
+  min-height: 0;
+  padding: 0;
+  overflow: hidden;
+  color: #ffffff;
+}
+
 @media (max-width: 576px) {
   .modal-shell {
     padding: 0.75rem;
@@ -128,4 +186,18 @@
     max-height: min(100dvh - 1.5rem, 48rem);
     border-radius: 1.25rem 1.25rem 0.75rem 0.75rem;
   }
+
+  .modal-shell--fullscreen-media {
+    align-items: center;
+    padding: 0;
+  }
+
+  .modal-shell--fullscreen-media .modal-shell__dialog {
+    height: 100dvh;
+  }
+
+  .modal-shell--fullscreen-media .modal-shell__content {
+    max-height: none;
+    border-radius: 0;
+  }
 }

src/app/shared/components/modal-shell/modal-shell.component.ts

@@ -9,7 +9,7 @@ import {
   viewChild,
 } from '@angular/core';
 
-import { ModalSize } from '../../../core/services/modal.service';
+import { ModalPresentation, ModalSize } from '../../../core/services/modal.service';
 
 @Component({
   selector: 'app-modal-shell',
@@ -23,6 +23,7 @@ export class ModalShellComponent {
 
   readonly title = input<string | undefined>();
   readonly size = input<ModalSize>('md');
+  readonly presentation = input<ModalPresentation>('dialog');
   readonly showCloseButton = input(true);
 
   readonly backdropClick = output<void>();