EPUB/snapshot: Don't throw when navigating past end of nav stack

zotero · Sep 26, 2023 · 90b09e8 · 90b09e8
1 parent 6baeadc
commit 90b09e8
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Showing 2 changed files with 20 additions and 12 deletions.
diff --git a/src/dom/epub/epub-view.ts b/src/dom/epub/epub-view.ts
@@ -910,17 +910,21 @@ class EPUBView extends DOMView<EPUBViewState, EPUBViewData> {
 
 	// This is like back/forward navigation in browsers. Try Cmd-ArrowLeft and Cmd-ArrowRight in PDF view
 	navigateBack() {
-		this.navigate({ pageNumber: this._navStack.popBack() }, {
-			skipNavStack: true,
-			behavior: 'auto',
-		});
+		if (this._navStack.canPopBack()) {
+			this.navigate({ pageNumber: this._navStack.popBack() }, {
+				skipNavStack: true,
+				behavior: 'auto',
+			});
+		}
 	}
 
 	navigateForward() {
-		this.navigate({ pageNumber: this._navStack.popForward() }, {
-			skipNavStack: true,
-			behavior: 'auto',
-		});
+		if (this._navStack.canPopForward()) {
+			this.navigate({ pageNumber: this._navStack.popForward() }, {
+				skipNavStack: true,
+				behavior: 'auto',
+			});
+		}
 	}
 
 	navigateToFirstPage() {

diff --git a/src/dom/snapshot/snapshot-view.ts b/src/dom/snapshot/snapshot-view.ts
@@ -459,13 +459,17 @@ class SnapshotView extends DOMView<SnapshotViewState, SnapshotViewData> {
 	}
 
 	navigateBack() {
-		this._iframeWindow.scrollTo(...this._navStack.popBack());
-		this._handleViewUpdate();
+		if (this._navStack.canPopBack()) {
+			this._iframeWindow.scrollTo(...this._navStack.popBack());
+			this._handleViewUpdate();
+		}
 	}
 
 	navigateForward() {
-		this._iframeWindow.scrollTo(...this._navStack.popForward());
-		this._handleViewUpdate();
+		if (this._navStack.canPopForward()) {
+			this._iframeWindow.scrollTo(...this._navStack.popForward());
+			this._handleViewUpdate();
+		}
 	}
 
 	// Still need to figure out how this is going to work