From dacf15f02497661b642dd7df937609cb2c8d6c5e Mon Sep 17 00:00:00 2001
From: Joseph Milazzo <joseph.v.milazzo@gmail.com>
Date: Wed, 29 Jun 2022 19:48:29 -0500
Subject: [PATCH] Manga Reader Double Layout bugfixes (#1341)

* Enforce some max heights on series detail page

* Added some icon to layout mode to help the user understand how they work (Robbie needs to css it)

* Adding split-double icon

* Fixing reverse

* Added lots of debug code, refactored documentation, and added some history for wide images

* More prefetching code for wide images

* Fixed the issue where sometimes paging backwards would skip an image

* Fixed up a bug where occasionally on double (manga) paging backwards could skip a page.

Fixed a bug on double where last page could get duplicated.

* Don't update pageDimensionHistory since we don't need it

* Forgot some changes

Co-authored-by: Robbie Davis <robbie@therobbiedavis.com>
---
 .../cards/list-item/list-item.component.html  |   2 +-
 .../manga-reader/manga-reader.component.html  |  47 +++++-
 .../manga-reader/manga-reader.component.scss  |  25 ++-
 .../manga-reader/manga-reader.component.ts    | 149 ++++++++++++++----
 .../series-detail.component.html              |   2 +-
 5 files changed, 188 insertions(+), 37 deletions(-)

diff --git a/UI/Web/src/app/cards/list-item/list-item.component.html b/UI/Web/src/app/cards/list-item/list-item.component.html
index 3fd626f73..2c3b846fd 100644
--- a/UI/Web/src/app/cards/list-item/list-item.component.html
+++ b/UI/Web/src/app/cards/list-item/list-item.component.html
@@ -1,6 +1,6 @@
 <div class="list-item-container d-flex flex-row g-0 mb-2 p-2">
     <div class="pe-2">
-        <app-image [imageUrl]="imageUrl" [height]="imageHeight" [width]="imageWidth"></app-image>
+        <app-image [imageUrl]="imageUrl" [height]="imageHeight" maxHeight="200px" [width]="imageWidth"></app-image>
         <div class="not-read-badge" *ngIf="pagesRead === 0 && totalPages > 0"></div>
         <span class="download" *ngIf="download$ | async as download">
             <app-circular-loader [currentValue]="download.progress"></app-circular-loader>
diff --git a/UI/Web/src/app/manga-reader/manga-reader.component.html b/UI/Web/src/app/manga-reader/manga-reader.component.html
index 07afaebe4..4aebd4380 100644
--- a/UI/Web/src/app/manga-reader/manga-reader.component.html
+++ b/UI/Web/src/app/manga-reader/manga-reader.component.html
@@ -13,6 +13,9 @@
                 </div>
             </div>
 
+            {{readerService.imageUrlToPageNum(this.canvasImage.src)}}
+            {{readerService.imageUrlToPageNum(this.canvasImage2.src)}}
+
             <div style="margin-left: auto; padding-right: 3%;">
                 <button class="btn btn-icon btn-small" title="Shortcuts" (click)="openShortcutModal()">
                     <i class="fa-regular fa-rectangle-list" aria-hidden="true"></i>
@@ -63,13 +66,12 @@
             <div class="image-container {{getFittingOptionClass()}}" [ngClass]="{'d-none': renderWithCanvas, 'center-double': ShouldRenderDoublePage,
                     'fit-to-width-double-offset' : FittingOption === FITTING_OPTION.WIDTH && ShouldRenderDoublePage,
                     'fit-to-height-double-offset': FittingOption === FITTING_OPTION.HEIGHT && ShouldRenderDoublePage,
-                    'original-double-offset' : FittingOption === FITTING_OPTION.ORIGINAL && ShouldRenderDoublePage,
-                    'reverse': ShouldRenderReverseDouble}">
+                    'original-double-offset' : FittingOption === FITTING_OPTION.ORIGINAL && ShouldRenderDoublePage}">
                 <img #image [src]="canvasImage.src" id="image-1"
                     class="{{getFittingOptionClass()}} {{readerMode === ReaderMode.LeftRight || readerMode === ReaderMode.UpDown ? '' : 'd-none'}} {{showClickOverlay ? 'blur' : ''}}">
 
-                <ng-container *ngIf="(ShouldRenderDoublePage || ShouldRenderReverseDouble) && (this.pageNum <= maxPages - 1 && this.pageNum > 0)">
-                    <img [src]="canvasImage2.src" id="image-2"  class="image-2 {{getFittingOptionClass()}} {{readerMode === ReaderMode.LeftRight || readerMode === ReaderMode.UpDown ? '' : 'd-none'}} {{showClickOverlay ? 'blur' : ''}} {{ShouldRenderReverseDouble ? 'reverse' : ''}}">
+                <ng-container *ngIf="(this.canvasImage2.src !== '') && (readerService.imageUrlToPageNum(canvasImage2.src) <= maxPages - 1 && !isCoverImage())">
+                    <img [src]="canvasImage2.src" id="image-2" class="image-2 {{getFittingOptionClass()}} {{readerMode === ReaderMode.LeftRight || readerMode === ReaderMode.UpDown ? '' : 'd-none'}} {{showClickOverlay ? 'blur' : ''}}"> <!--  {{ShouldRenderReverseDouble ? 'reverse' : ''}} -->
                 </ng-container>
             </div>
 
@@ -162,7 +164,42 @@
 
                 <div class="row mb-2">
                     <div class="col-md-6 col-sm-12">
-                        <label for="layout-mode" class="form-label">Layout Mode</label>
+                        <label for="layout-mode" class="form-label">Layout Mode</label>&nbsp;
+                            <ng-container [ngSwitch]="layoutMode">
+                                <ng-container *ngSwitchCase="LayoutMode.Single">
+                                    <div class="split-double">
+                                        <span class="fa-stack fa-1x">
+                                            <i class="fa-regular fa-square-full fa-stack-2x"></i>
+                                            <i class="fa fa-image fa-stack-1x"></i>
+                                          </span>
+                                    </div>
+                                </ng-container>
+                                <ng-container *ngSwitchCase="LayoutMode.Double">
+                                    <div class="split-double">
+                                        <span class="fa-stack fa-1x">
+                                            <i class="fa-regular fa-square-full fa-stack-2x"></i>
+                                            <i class="fab fa-1 fa-stack-1x"></i>
+                                          </span>
+                                          <span class="fa-stack fa right">
+                                            <i class="fa-regular fa-square-full fa-stack-2x"></i>
+                                            <i class="fab fa-2 fa-stack-1x"></i>
+                                          </span>
+                                    </div>
+                                </ng-container>
+                                <ng-container *ngSwitchCase="LayoutMode.DoubleReversed">
+                                    <div class="split-double">
+                                        <span class="fa-stack fa-1x">
+                                            <i class="fa-regular fa-square-full fa-stack-2x"></i>
+                                            <i class="fab fa-2 fa-stack-1x"></i>
+                                          </span>
+                                          <span class="fa-stack fa right">
+                                            <i class="fa-regular fa-square-full fa-stack-2x"></i>
+                                            <i class="fab fa-1 fa-stack-1x"></i>
+                                          </span>
+                                    </div>                                   
+                                </ng-container>
+                                <!-- <div class="{{LayoutModeIconClass}}"></div> -->
+                            </ng-container>
                         <select class="form-control" id="page-fitting" formControlName="layoutMode">
                             <option [value]="opt.value" *ngFor="let opt of layoutModes">{{opt.text}}</option>
                         </select>
diff --git a/UI/Web/src/app/manga-reader/manga-reader.component.scss b/UI/Web/src/app/manga-reader/manga-reader.component.scss
index b07cd02e9..93ef33a76 100644
--- a/UI/Web/src/app/manga-reader/manga-reader.component.scss
+++ b/UI/Web/src/app/manga-reader/manga-reader.component.scss
@@ -57,9 +57,14 @@ img {
   }
 
   &.reverse {
-    flex-direction: row-reverse;
     overflow: unset;
-    justify-content: flex-end;
+    display: flex;
+    align-content: center;
+    justify-content: center;
+
+    img {
+      margin: unset;
+    }
   }
   
   #image-2 {
@@ -172,6 +177,7 @@ img {
     overflow: hidden;
     border: 2px solid #ccc;
     vertical-align: sub;
+    display: inline-block;
 
     &::before {
         margin-left: 30%;
@@ -197,8 +203,21 @@ img {
     .none {
         background-color: rgba(255, 255, 255, 0.5);
     }
+
+    // For layout only
+
   }
-  
+
+  .split-double {
+    height: 20px;
+    display: inline-block;
+    font-size: .7em;
+
+    .right {
+      left: -7px;
+    }
+  }
+
   ::ng-deep {
     .custom-slider .ngx-slider .ngx-slider-bar {
       background: #e9ffe2;
diff --git a/UI/Web/src/app/manga-reader/manga-reader.component.ts b/UI/Web/src/app/manga-reader/manga-reader.component.ts
index 3d13fa078..5cd1f4806 100644
--- a/UI/Web/src/app/manga-reader/manga-reader.component.ts
+++ b/UI/Web/src/app/manga-reader/manga-reader.component.ts
@@ -38,6 +38,7 @@ const OVERLAY_AUTO_CLOSE_TIME = 3000;
 const CLICK_OVERLAY_TIMEOUT = 3000;
 
 
+
 @Component({
   selector: 'app-manga-reader',
   templateUrl: './manga-reader.component.html',
@@ -66,6 +67,14 @@ const CLICK_OVERLAY_TIMEOUT = 3000;
   ]
 })
 export class MangaReaderComponent implements OnInit, AfterViewInit, OnDestroy {
+
+
+  @ViewChild('reader') reader!: ElementRef;
+  @ViewChild('readingArea') readingArea!: ElementRef;
+  @ViewChild('content') canvas: ElementRef | undefined;
+  @ViewChild('image') image!: ElementRef;
+
+
   libraryId!: number;
   seriesId!: number;
   volumeId!: number;
@@ -123,33 +132,41 @@ export class MangaReaderComponent implements OnInit, AfterViewInit, OnDestroy {
    */
   isLoose = false;
 
-  @ViewChild('reader') reader!: ElementRef;
-  @ViewChild('readingArea') readingArea!: ElementRef;
-  @ViewChild('content') canvas: ElementRef | undefined;
-  @ViewChild('image') image!: ElementRef;
+
   private ctx!: CanvasRenderingContext2D;
   /**
-   * Used to render a page on the canvas or in the image tag. This Image element is prefetched by the cachedImages buffer
+   * Used to render a page on the canvas or in the image tag. This Image element is prefetched by the cachedImages buffer.
+   * @remarks Used for rendering to screen.
    */
   canvasImage = new Image();
   /**
-   * Used solely for LayoutMode.Double rendering. Will always hold the next image in buffer.
+   * Used solely for LayoutMode.Double rendering. 
+   * @remarks Used for rendering to screen.
    */
   canvasImage2 = new Image();
   /**
-   * Used solely for LayoutMode.Double rendering. Will always hold the previous image in buffer.
+   * Used solely for LayoutMode.Double rendering. Will always hold the previous image to canvasImage
+   * @see canvasImage
    */
   canvasImagePrev = new Image();
   /**
-   * Used solely for LayoutMode.Double rendering. Will always hold the next image in buffer.
+   * Used solely for LayoutMode.Double rendering. Will always hold the next image to canvasImage
+   * @see canvasImage
    */
   canvasImageNext = new Image();
   /**
-   * Used solely for LayoutMode.DoubleReverse rendering. Will always hold the image after next in buffer.
+   * Responsible to hold current page + 2. Used to know if we should render 
+   * @remarks Used solely for LayoutMode.DoubleReverse rendering. 
    */
-   canvasImageNextDouble = new Image();
+   canvasImageAheadBy2 = new Image();
+   /**
+   * Responsible to hold current page -2 2. Used to know if we should render 
+   * @remarks Used solely for LayoutMode.DoubleReverse rendering. 
+   */
+   canvasImageBehindBy2 = new Image();
   /**
-   * Dictates if we use render with canvas or with image. This is only for Splitting.
+   * Dictates if we use render with canvas or with image. 
+   * @remarks This is only for Splitting.
    */
   renderWithCanvas: boolean = false;
 
@@ -296,25 +313,32 @@ export class MangaReaderComponent implements OnInit, AfterViewInit, OnDestroy {
     return Math.max(Math.min(this.pageNum, this.maxPages - 1), 0);
   }
 
+  /**
+   * Determines if we should render a double page.
+   * The general gist is if we are on double layout mode, the current page (first page) is not a cover image or a wide image 
+   * and the next page is not a wide image (as only non-wides should be shown next to each other).
+   * @remarks This will always fail if the window's width is greater than the height
+   */
   get ShouldRenderDoublePage() {
+    // window.innerWidth > window.innerHeight // Don't render double if orientation is portrait, mostly mobile
     return (
       this.layoutMode === LayoutMode.Double &&
       !this.isCoverImage() &&
       !this.isWideImage(this.canvasImage) && 
-      !this.isWideImage(this.canvasImageNext) &&
-      window.innerWidth > window.innerHeight // Don't render double if orientation is portrait, mostly mobile
+      !this.isWideImage(this.canvasImageNext)
       );
   }
 
   get ShouldRenderReverseDouble() {
+    // NOTE: I'm not going to care about window.innerWidth > window.innerHeight since a higher level handler will manage
+    // window.innerWidth > window.innerHeight // Don't render double reversed if orientation is portrait, mostly mobile
     return (
       this.layoutMode === LayoutMode.DoubleReversed &&
       !this.isCoverImage() &&
       !this.isCoverImage(this.pageNum - 1) &&
       !this.isWideImage(this.canvasImage) &&
       !this.isWideImage(this.canvasImageNext) &&
-      !this.isLoose &&
-      window.innerWidth > window.innerHeight // Don't render double reversed if orientation is portrait, mostly mobile
+      !this.isLoose
       );
   }
 
@@ -372,6 +396,17 @@ export class MangaReaderComponent implements OnInit, AfterViewInit, OnDestroy {
     return 'right-side';
   }
 
+  get LayoutModeIconClass() {
+    switch (this.layoutMode) {
+      case LayoutMode.Single:
+        return 'none';
+      case LayoutMode.Double:
+        return 'double';
+      case LayoutMode.DoubleReversed:
+        return 'double-reversed';
+    }
+  }
+
   get ReaderModeIcon() {
     switch(this.readerMode) {
       case ReaderMode.LeftRight:
@@ -960,6 +995,12 @@ export class MangaReaderComponent implements OnInit, AfterViewInit, OnDestroy {
 
     const notInSplit = this.currentImageSplitPart !== (this.isSplitLeftToRight() ? SPLIT_PAGE_PART.LEFT_PART : SPLIT_PAGE_PART.RIGHT_PART);
 
+    // console.log('Current, Next: ', this.readerService.imageUrlToPageNum(this.canvasImage.src), ',', this.readerService.imageUrlToPageNum(this.canvasImageNext.src));
+    // console.log('Is canvasImage wide: ', this.isWideImage(this.canvasImage));
+    // console.log('Is canvasImage next wide: ', this.isWideImage(this.canvasImageNext));
+    // console.log('PRev: ', this.readerService.imageUrlToPageNum(this.canvasImagePrev.src));
+
+
     let pageAmount = 1;
     if (this.layoutMode === LayoutMode.Double) {
       pageAmount = (
@@ -969,12 +1010,11 @@ export class MangaReaderComponent implements OnInit, AfterViewInit, OnDestroy {
         !this.isSecondLastImage() &&
         !this.isLastImage()
         ? 2 : 1);
-    }
-    if (this.layoutMode === LayoutMode.DoubleReversed) {
+    } else if (this.layoutMode === LayoutMode.DoubleReversed) {
       pageAmount = (
-        !this.isCoverImage(this.pageNum - 1) &&
-        !this.isWideImage(this.canvasImagePrev) &&
-        !this.isWideImage(this.canvasImageNextDouble) &&
+        //!this.isCoverImage(this.pageNum - 1) && // 
+        !this.isWideImage(this.canvasImageNext) && 
+        !this.isWideImage(this.canvasImageAheadBy2) && // Remember we are doing this logic before we've hit the next page, so we need this
         !this.isSecondLastImage() &&
         !this.isLastImage()
         ? 2 : 1);
@@ -1014,16 +1054,27 @@ export class MangaReaderComponent implements OnInit, AfterViewInit, OnDestroy {
 
     let pageAmount = 1;
     if (this.layoutMode === LayoutMode.Double) {
+      // Current is current and next is current + 1 (current is the page we are paging from)
+      // console.log('Current, Next: ', this.readerService.imageUrlToPageNum(this.canvasImage.src), ',', this.readerService.imageUrlToPageNum(this.canvasImageNext.src));
+      // console.log('Is canvasImage wide: ', this.isWideImage(this.canvasImage));
+      // console.log('Is canvasImage next wide: ', this.isWideImage(this.canvasImageNext));
+      // console.log('PRev: ', this.readerService.imageUrlToPageNum(this.canvasImagePrev.src)); // Prev is actually currentPage - 1 on double
+
       pageAmount = (
         !this.isCoverImage() &&
         !this.isWideImage(this.canvasImagePrev)
         ? 2 : 1);
     }
     if (this.layoutMode === LayoutMode.DoubleReversed) {
+      // Current is current - 1 and next is current -2 (current is the page we are paging from)
+      // console.log('Current, Next: ', this.readerService.imageUrlToPageNum(this.canvasImage.src), ',', this.readerService.imageUrlToPageNum(this.canvasImageNext.src));
+      // console.log('Is canvasImage wide: ', this.isWideImage(this.canvasImage));
+      // console.log('Is canvasImage next wide: ', this.isWideImage(this.canvasImageNext));
+      // console.log('PRev: ', this.readerService.imageUrlToPageNum(this.canvasImagePrev.src)); // Prev is actually currentPage + 1 on double reversed
       pageAmount = (
         !this.isCoverImage() &&
         !this.isCoverImage(this.pageNum - 1) &&
-        !this.isWideImage(this.canvasImage) &&
+        !this.isWideImage(this.canvasImage) && // JOE: At this point, these aren't yet set to the new values
         !this.isWideImage(this.canvasImageNext)
         ? 2 : 1);
     }
@@ -1202,24 +1253,41 @@ export class MangaReaderComponent implements OnInit, AfterViewInit, OnDestroy {
       this.generalSettingsForm.get('fittingOption')?.setValue(newScale, {emitEvent: false});
   }
 
+  /**
+   * If pagenumber is 0 aka first page, which on double page rendering should always render as a single. 
+   * 
+   * @param pageNumber Defaults to current page number
+   * @returns 
+   */
   isCoverImage(pageNumber = this.pageNum) {
     return pageNumber === 0;
   }
 
+  /**
+   * If the image's width is greater than it's height
+   * @param elem Optional Image
+   */
   isWideImage(elem?: HTMLImageElement) {
     if (elem) {
       elem.onload = () => {
         return elem.width > elem.height;
       }
+      if (elem.src === '') return false;
     }
     const element = elem || this.canvasImage;
     return element.width > element.height;
   }
 
+  /**
+   * If the current page is second to last image
+   */
   isSecondLastImage() {
     return this.maxPages - 1 - this.pageNum === 1;
   }
 
+  /**
+   * If the current image is last image
+   */
   isLastImage() {
     return this.maxPages - 1 === this.pageNum;
   }
@@ -1230,7 +1298,10 @@ export class MangaReaderComponent implements OnInit, AfterViewInit, OnDestroy {
     return true;
   }
 
-
+  /**
+   * Maintains a circular array of images (that are requested from backend) around the user's current page. This allows for quick loading (seemless to user)
+   * and also maintains page info (wide image, etc) due to onload event.
+   */
   prefetch() {
     let index = 1;
 
@@ -1251,19 +1322,43 @@ export class MangaReaderComponent implements OnInit, AfterViewInit, OnDestroy {
     //console.log('cachedImages: ', this.cachedImages.arr.map(img => this.readerService.imageUrlToPageNum(img.src) + ': ' + img.complete));
   }
 
+
   loadPage() {
     this.isLoading = true;
     this.canvasImage2.src = '';
+    this.canvasImageAheadBy2.src = '';
+
     this.isLoose = (this.pageAmount === 1 ? true : false);
     this.canvasImage.src = this.getPageUrl(this.pageNum);
 
     if (this.layoutMode !== LayoutMode.Single) {
-      this.canvasImagePrev.src = this.getPageUrl(this.pageNum + (this.layoutMode !== LayoutMode.DoubleReversed ? - 1 : + 1));
-      this.canvasImageNext.src = this.getPageUrl(this.pageNum + (this.layoutMode !== LayoutMode.DoubleReversed ? + 1 : - 1));
-      this.canvasImageNextDouble.src = this.getPageUrl(this.pageNum + 2);
-      if (this.ShouldRenderDoublePage || this.ShouldRenderReverseDouble) {
-          this.canvasImage2.src = this.canvasImageNext.src;
+      this.canvasImageNext.src = this.getPageUrl(this.pageNum + 1); // This needs to be capped at maxPages !this.isLastImage()
+      this.canvasImagePrev.src = this.getPageUrl(this.pageNum - 1);
+
+      if (this.pageNum + 2 < this.maxPages - 1) {
+        this.canvasImageAheadBy2.src = this.getPageUrl(this.pageNum + 2);
       }
+      if (this.pageNum - 2 >= 0) {
+        this.canvasImageBehindBy2.src = this.getPageUrl(this.pageNum - 2 || 0);
+      }      
+    
+      if (this.ShouldRenderDoublePage || this.ShouldRenderReverseDouble) {
+        if (this.layoutMode === LayoutMode.Double) {
+          this.canvasImage2.src = this.canvasImageNext.src;
+        } else {
+          this.canvasImage2.src = this.canvasImagePrev.src;
+        }
+      }
+
+      // console.log('======================================================');
+      // console.log('Page History: ', this.pageDimensionHistory);
+      // console.log('Current Page: ', this.pageNum);
+      // console.log('CanvasImage page: ', this.readerService.imageUrlToPageNum(this.canvasImage.src));
+      // console.log('CanvasImage2 page: ', this.readerService.imageUrlToPageNum(this.canvasImage2.src));
+      // console.log('Canvas Image Next:', this.readerService.imageUrlToPageNum(this.canvasImageNext.src));
+      // console.log('Canvas Image Next Ahead by 2:', this.readerService.imageUrlToPageNum(this.canvasImageAheadBy2.src));
+      // console.log('Canvas Image Prev:', this.readerService.imageUrlToPageNum(this.canvasImagePrev.src));
+      // console.log('======================================================');
     }
     this.renderPage();
     this.prefetch();
diff --git a/UI/Web/src/app/series-detail/series-detail.component.html b/UI/Web/src/app/series-detail/series-detail.component.html
index 797849166..28ab165bd 100644
--- a/UI/Web/src/app/series-detail/series-detail.component.html
+++ b/UI/Web/src/app/series-detail/series-detail.component.html
@@ -57,7 +57,7 @@
 <div [ngStyle]="{'height': ScrollingBlockHeight}" class="main-container container-fluid pt-2" *ngIf="series !== undefined" #scrollingBlock>
     <div class="row mb-3 info-container">
         <div class="col-md-2 col-xs-4 col-sm-6 d-none d-sm-block">
-            <app-image maxWidth="300px" [imageUrl]="seriesImage"></app-image>
+            <app-image maxWidth="300px" maxHeight="400px" [imageUrl]="seriesImage"></app-image>
             <!-- NOTE: We can put continue point here as Vol X Ch Y or just Ch Y or Book Z ?-->
         </div>
         <div class="col-md-10 col-xs-8 col-sm-6 mt-2">