#383 Shift Key Modifier on the Commit Details View topological naviga…

…tion keystrokes.
mhutchie · Sep 19, 2020 · 7355d83 · 7355d83
1 parent 808878f
commit 7355d83
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Showing 2 changed files with 76 additions and 8 deletions.
diff --git a/web/graph.ts b/web/graph.ts
@@ -587,24 +587,82 @@ class Graph {
 		return muted;
 	}
 
+
+	/**
+	 * Get the index of the first parent of the commit at the specified index.
+	 * @param i The index of the commit.
+	 * @returns The index of the first parent, or -1 if there is no parent.
+	 */
 	public getFirstParentIndex(i: number) {
 		const parents = this.vertices[i].getParents();
-		return parents.length > 0 ? parents[0].id : -1;
+		return parents.length > 0
+			? parents[0].id
+			: -1;
 	}
 
+	/**
+	 * Get the index of the alternative parent of the commit at the specified index.
+	 * @param i The index of the commit.
+	 * @returns The index of the alternative parent, or -1 if there is no parent.
+	 */
+	public getAlternativeParentIndex(i: number) {
+		const parents = this.vertices[i].getParents();
+		return parents.length > 1
+			? parents[1].id
+			: parents.length === 1
+				? parents[0].id
+				: -1;
+	}
+
+	/**
+	 * Get the index of the first child of the commit at the specified index.
+	 * @param i The index of the commit.
+	 * @returns The index of the first child, or -1 if there is no child.
+	 */
 	public getFirstChildIndex(i: number) {
 		const children = this.vertices[i].getChildren();
-		if (children.length > 0) {
-			// The vertex has children
+		if (children.length > 1) {
+			// The vertex has multiple children
 			const branch = this.vertices[i].getBranch();
-			let childOnSameBranch;
+			let childOnSameBranch: Vertex | undefined;
 			if (branch !== null && (childOnSameBranch = children.find((child) => child.isOnThisBranch(branch)))) {
 				// If a child could be found on the same branch as the vertex
 				return childOnSameBranch.id;
 			} else {
 				// No child could be found on the same branch as the vertex
 				return Math.max(...children.map((child) => child.id));
 			}
+		} else if (children.length === 1) {
+			// The vertex has a single child
+			return children[0].id;
+		} else {
+			// The vertex has no children
+			return -1;
+		}
+	}
+
+	/**
+	 * Get the index of the alternative child of the commit at the specified index.
+	 * @param i The index of the commit.
+	 * @returns The index of the alternative child, or -1 if there is no child.
+	 */
+	public getAlternativeChildIndex(i: number) {
+		const children = this.vertices[i].getChildren();
+		if (children.length > 1) {
+			// The vertex has multiple children
+			const branch = this.vertices[i].getBranch();
+			let childOnSameBranch: Vertex | undefined;
+			if (branch !== null && (childOnSameBranch = children.find((child) => child.isOnThisBranch(branch)))) {
+				// If a child could be found on the same branch as the vertex
+				return Math.max(...children.filter(child => child !== childOnSameBranch).map((child) => child.id));
+			} else {
+				// No child could be found on the same branch as the vertex
+				const childIndexes = children.map((child) => child.id).sort();
+				return childIndexes[childIndexes.length - 2];
+			}
+		} else if (children.length === 1) {
+			// The vertex has a single child
+			return children[0].id;
 		} else {
 			// The vertex has no children
 			return -1;

diff --git a/web/main.ts b/web/main.ts
@@ -1819,10 +1819,20 @@ class GitGraphView {
 
 				if (e.ctrlKey || e.metaKey) {
 					// Up / Down navigates according to the order of commits on the branch
-					if (e.key === 'ArrowUp') {
-						newHashIndex = this.graph.getFirstChildIndex(curHashIndex);
-					} else if (e.key === 'ArrowDown') {
-						newHashIndex = this.graph.getFirstParentIndex(curHashIndex);
+					if (e.shiftKey) {
+						// Follow commits on alternative branches when possible
+						if (e.key === 'ArrowUp') {
+							newHashIndex = this.graph.getAlternativeChildIndex(curHashIndex);
+						} else if (e.key === 'ArrowDown') {
+							newHashIndex = this.graph.getAlternativeParentIndex(curHashIndex);
+						}
+					} else {
+						// Follow commits on the same branch
+						if (e.key === 'ArrowUp') {
+							newHashIndex = this.graph.getFirstChildIndex(curHashIndex);
+						} else if (e.key === 'ArrowDown') {
+							newHashIndex = this.graph.getFirstParentIndex(curHashIndex);
+						}
 					}
 				} else {
 					// Up / Down navigates according to the order of commits in the table