Custom Cover Images (#499)

* Added some documentation. Removed Require Admin Role from Search Tags. Added Summary to be updated on UpdateTag.

* Added Swagger xml doc generation to beef up the documentation. Started adding xml comments to the APIs. This is a needed, slow task for upcoming Plugins system.

* Implemented the ability to upload a custom series image to override the existing cover image.

Refactored some code out to use ImageService and added more documentation

* When a page cache fails, delete cache directory so user can try to reload.

* Implemented the ability to lock a series cover image such that after user uploads something, it wont get refreshed by Kavita.

* Implemented the ability to reset cover image for series by unlocking

* Kick off a series refresh after a cover is unlocked.

* Ability to press enter to load a url

* Ability to reset selection

* Cleaned up cover chooser such that reset is nicer, errors inform user to use file upload, series edit modal now doesn't use scrollable body. Mobile tweaks. CoverImageLocked is now sent to the UI.

* More css changes to look better

* When no bookmarks, don't show both markups

* Fixed issues where images wouldn't refresh after cover image was changed.

* Implemented the ability to change the cover images for collection tags.

* Added property and API for chapter cover image update

* Added UI code to prepare for updating cover image for chapters. need to rearrange components

* Moved a ton of code around to separate card related screens into their own module.

* Implemented the ability to update a chapter/volume cover image

* Refactored action for volume to say edit to reflect modal action

* Fixed issue where after editing chapter cover image, the underlying card wouldn't update

* Fixed an issue where we were passing volumeId to the reset chapter lock. Changed some logic in volume cover image generation.

* Automatically apply when you hit reset cover image

UI/Web/src/app/cards/cover-image-chooser/cover-image-chooser.component.ts

@@ -0,0 +1,187 @@
+import { Component, EventEmitter, Input, OnDestroy, OnInit, Output } from '@angular/core';
+import { FormBuilder, FormControl, FormGroup } from '@angular/forms';
+import { NgxFileDropEntry, FileSystemFileEntry } from 'ngx-file-drop';
+import { fromEvent, Subject } from 'rxjs';
+import { takeWhile } from 'rxjs/operators';
+import { ToastrService } from 'ngx-toastr';
+import { ImageService } from 'src/app/_services/image.service';
+import { KEY_CODES } from 'src/app/shared/_services/utility.service';
+
+@Component({
+  selector: 'app-cover-image-chooser',
+  templateUrl: './cover-image-chooser.component.html',
+  styleUrls: ['./cover-image-chooser.component.scss']
+})
+export class CoverImageChooserComponent implements OnInit, OnDestroy {
+
+  @Input() imageUrls: Array<string> = [];
+  @Output() imageUrlsChange: EventEmitter<Array<string>> = new EventEmitter<Array<string>>();
+
+  /**
+   * Should the control give the ability to select an image that emits the reset status for cover image
+   */
+  @Input() showReset: boolean = false;
+  @Output() resetClicked: EventEmitter<void> = new EventEmitter<void>();
+
+  /**
+   * Emits the selected index. Used usually to check if something other than the default image was selected.
+   */
+  @Output() imageSelected: EventEmitter<number> = new EventEmitter<number>();
+  /**
+   * Emits a base64 encoded image
+   */
+  @Output() selectedBase64Url: EventEmitter<string> = new EventEmitter<string>();
+
+
+
+  selectedIndex: number = 0;
+  form!: FormGroup;
+  files: NgxFileDropEntry[] = [];
+
+  mode: 'file' | 'url' | 'all' = 'all';
+  private readonly onDestroy = new Subject<void>();
+
+  constructor(public imageService: ImageService, private fb: FormBuilder, private toastr: ToastrService) { }
+
+  ngOnInit(): void {
+    this.form = this.fb.group({
+      coverImageUrl: new FormControl('', [])
+    });
+  }
+
+  ngOnDestroy() {
+    this.onDestroy.next();
+    this.onDestroy.complete();
+  }
+
+  getBase64Image(img: HTMLImageElement) {
+    const canvas = document.createElement("canvas");
+    canvas.width = img.width;
+    canvas.height = img.height;
+    const ctx = canvas.getContext("2d", {alpha: false});
+    if (!ctx) {
+      return '';
+    }
+
+    ctx.drawImage(img, 0, 0);
+    var dataURL = canvas.toDataURL("image/png");
+    return dataURL;
+  }
+
+  selectImage(index: number) {
+    if (this.selectedIndex === index) { return; }
+    this.selectedIndex = index;
+    this.imageSelected.emit(this.selectedIndex);
+    const selector = `.chooser img[src="${this.imageUrls[this.selectedIndex]}"]`;
+
+    
+    const elem = document.querySelector(selector) || document.querySelectorAll('.chooser img.card-img-top')[this.selectedIndex];
+    if (elem) {
+      const imageElem = <HTMLImageElement>elem;
+      if (imageElem.src.startsWith('data')) {
+        this.selectedBase64Url.emit(imageElem.src);
+        return;
+      }
+      const image = this.getBase64Image(imageElem);
+      if (image != '') {
+        this.selectedBase64Url.emit(image);
+      }
+    }
+  }
+
+  loadImage() {
+    const url = this.form.get('coverImageUrl')?.value.trim();
+    if (url && url != '') {
+      const img = new Image();
+      img.crossOrigin = 'Anonymous';
+      img.src = this.form.get('coverImageUrl')?.value;
+      img.onload = (e) => this.handleUrlImageAdd(e);
+      img.onerror = (e) => {
+        this.toastr.error('The image could not be fetched due to server refusing request. Please download and upload from file instead.');
+        this.form.get('coverImageUrl')?.setValue('');  
+      }
+      this.form.get('coverImageUrl')?.setValue('');
+    }
+  }
+  
+
+
+  
+
+  public dropped(files: NgxFileDropEntry[]) {
+    this.files = files;
+    for (const droppedFile of files) {
+
+      // Is it a file?
+      if (droppedFile.fileEntry.isFile) {
+        const fileEntry = droppedFile.fileEntry as FileSystemFileEntry;
+        fileEntry.file((file: File) => {
+          const reader  = new FileReader();
+          reader.onload = (e) => this.handleFileImageAdd(e);
+          reader.readAsDataURL(file);
+        });
+      }
+    }
+  }
+
+  handleFileImageAdd(e: any) {
+    if (e.target == null) return;
+
+    this.imageUrls.push(e.target.result);
+    this.imageUrlsChange.emit(this.imageUrls);
+    this.selectedIndex += 1;
+    this.imageSelected.emit(this.selectedIndex); // Auto select newly uploaded image
+    this.selectedBase64Url.emit(e.target.result);
+  }
+
+  handleUrlImageAdd(e: any) {
+    console.log(e);
+    if (e.path === null || e.path.length === 0) return;
+
+    const url = this.getBase64Image(e.path[0]);
+    this.imageUrls.push(url);
+    this.imageUrlsChange.emit(this.imageUrls);
+
+    setTimeout(() => {
+      // Auto select newly uploaded image and tell parent of new base64 url
+      this.selectImage(this.selectedIndex + 1)
+    });
+  }
+
+  public fileOver(event: any){
+  }
+
+  public fileLeave(event: any){
+  }
+
+  reset() {
+    this.resetClicked.emit();
+    this.selectedIndex = -1;
+  }
+
+  setupEnterHandler() {
+    setTimeout(() => {
+      const elem = document.querySelector('input[id="load-image"]');
+      if (elem == null) return;
+      fromEvent(elem, 'keydown')
+        .pipe(takeWhile(() => this.mode === 'url')).subscribe((event) => {
+          const evt = <KeyboardEvent>event;
+          switch(evt.key) {
+            case KEY_CODES.ENTER:
+            {
+              this.loadImage();
+              break;
+            }
+      
+            case KEY_CODES.ESC_KEY:
+              this.mode = 'all';
+              event.stopPropagation();
+              break;
+            default:
+              break;
+          }
+        });
+    });
+  }
+
+}