feat: Insert heading at current, higher and deeper level (#10)

* Add v0 implementation of 'insert heading' feature

* Fix some little index bugs

* Fix conditional line assignment

* Add additional test

* doc: add document of insert headings

Co-authored-by: kasahala <[email protected]>

README.md

@@ -6,10 +6,6 @@
 
 Easily Shift and Change markdown headings.
 
-## Demo
-
-![Demo](https://raw.githubusercontent.com/k4a-dev/obsidian-heading-shifter/main/doc/attachment/shiftHeadings.gif)
-
 ## Why use this plugin
 
 Obsidian links numerous markdown files to form knowledge. Daily rearrangement of links is important to create a good knowledge base.
@@ -41,7 +37,7 @@ Download directory(includes `main.js, manifest.json, styles.css`) from the lates
 
 ## Features
 
-### Applying Heading
+### Apply Headings
 
 ![Applying Heading Demo](https://raw.githubusercontent.com/k4a-dev/obsidian-heading-shifter/main/doc/attachment/applyingHeading.gif)
 
@@ -54,7 +50,7 @@ Download directory(includes `main.js, manifest.json, styles.css`) from the lates
 
 > It is useful to assign a hotkey such as `Ctrl + 0 ~ 6`
 
-### Headings Shift
+### Shift Headings
 
 ![Headings Shift Demo](https://raw.githubusercontent.com/k4a-dev/obsidian-heading-shifter/main/doc/attachment/shiftHeadings.gif)
 
@@ -79,6 +75,44 @@ Download directory(includes `main.js, manifest.json, styles.css`) from the lates
 -   `Increase Headings` is ineffective if selected lines contains less than `Lower limit of Heading`.
 -   `Decrease Headings` is ineffective if selected lines contains more than heading 6.
 
+### Insert Headings
+
+#### Commands
+
+| Command                            | Description                                       | Hotkey |
+| ---------------------------------- | ------------------------------------------------- | ------ |
+| Insert Heading at current level    | Change current line headings to current level     |        |
+| Insert Heading at one level deeper | Change current line headings to current level + 1 |        |
+| Insert Heading at one level higher | Change current line headings to current level - 1 |        |
+
+#### Use Case
+
+Operate headings like an outliner like the following,
+
+```markdown
+# The Festival Myster -> hit "Apply 1"
+
+This is a great document.
+
+## Chapter One -> hit "Insert deeper"
+
+### Prologue -> hit "Insert deeper"
+
+The sun was setting over the horizon...
+
+### The Summer Festival -> hit "Insert current"
+
+As the townspeople gathered in the town square...
+
+## Chapter Two -> hit "Insert higher"
+
+### The Mystery of the Missing Prize -> hit "Insert deeper"
+
+As the summer festival came to a close...
+```
+
+If you want to make headings deeper or higher than 2, use "shift" or "apply".
+
 ## Loadmap
 
 Nothing specific at this time.

src/features/insertHeading/index.ts

@@ -0,0 +1 @@
+export { createInsertHeadingAtCurrentLevelCommand, createInsertHeadingAtDeeperLevelCommand, createInsertHeadingAtHigherLevelCommand } from "./operation";

src/features/insertHeading/operation.ts

@@ -0,0 +1,103 @@
+import { applyHeading } from "features/applyHeading";
+import { Command, Editor, Notice } from "obsidian";
+import { composeLineChanges } from "utils/editorChange";
+import { checkHeading, getPreviousHeading } from "utils/markdown";
+
+export const createInsertHeadingAtCurrentLevelCommand = (): Command => {
+	const createEditorCallback = () => {
+		return (editor: Editor) => {
+
+			const cursorLine = editor.getCursor("from").line
+			const lastHeadingLine = getPreviousHeading(editor, cursorLine)
+
+			// current heading level == most recently added heading
+			// 0 if no heading exists yet
+			const headingLevel = lastHeadingLine != undefined ? checkHeading(editor.getLine(lastHeadingLine)) : 0
+
+			editor.transaction({
+				changes: composeLineChanges(editor, [cursorLine], (chunk: string) =>
+					applyHeading(chunk, headingLevel)
+				),
+			});
+
+			editor.setCursor(editor.getCursor().line)
+			return
+		};
+	};
+
+	// return command object
+	return {
+		id: `insert-heading-current`,
+		name: `Insert Heading at current level`,
+		icon: `headingShifter_heading`,
+		editorCallback: createEditorCallback(),
+	};
+};
+
+
+export const createInsertHeadingAtDeeperLevelCommand = (): Command => {
+	const createEditorCallback = () => {
+		return (editor: Editor) => {
+
+			const cursorLine = editor.getCursor("from").line
+			const lastHeadingLine = getPreviousHeading(editor, cursorLine)
+
+			// current heading level == most recently added heading
+			// 0 if no heading exists yet
+			const headingLevel = lastHeadingLine ? checkHeading(editor.getLine(lastHeadingLine)) : 0
+
+			if (headingLevel+1 > 6) {
+				new Notice("Cannot Increase (contains more than Heading 6)");
+				return true;
+			}
+
+			editor.transaction({
+				changes: composeLineChanges(editor, [cursorLine], (chunk: string) =>
+					applyHeading(chunk, headingLevel + 1)
+				),
+			});
+
+			editor.setCursor(editor.getCursor().line)
+			return
+		};
+	};
+
+	// return command object
+	return {
+		id: `insert-heading-deeper`,
+		name: `Insert Heading at one level deeper`,
+		icon: `headingShifter_heading`,
+		editorCallback: createEditorCallback(),
+	};
+};
+
+export const createInsertHeadingAtHigherLevelCommand = (): Command => {
+	const createEditorCallback = () => {
+		return (editor: Editor) => {
+
+			const cursorLine = editor.getCursor("from").line
+			const lastHeadingLine = getPreviousHeading(editor, cursorLine)
+
+			// current heading level == most recently added heading
+			// 0 if no heading exists yet
+			const headingLevel = lastHeadingLine ? checkHeading(editor.getLine(lastHeadingLine)) : 0
+
+			editor.transaction({
+				changes: composeLineChanges(editor, [cursorLine], (chunk: string) =>
+					applyHeading(chunk, headingLevel - 1)
+				),
+			});
+
+			editor.setCursor(editor.getCursor().line)
+			return
+		};
+	};
+
+	// return command object
+	return {
+		id: `insert-heading-higher`,
+		name: `Insert Heading at one level higher`,
+		icon: `headingShifter_heading`,
+		editorCallback: createEditorCallback(),
+	};
+};

src/services/registerService.ts

@@ -1,5 +1,6 @@
 import { createApplyHeadingCommand } from "features/applyHeading";
 import { IncreaseHeading, DecreaseHeading } from "features/shiftHeading";
+import { createInsertHeadingAtCurrentLevelCommand, createInsertHeadingAtDeeperLevelCommand, createInsertHeadingAtHigherLevelCommand } from "features/insertHeading";
 import HeadingShifter from "main";
 import { HEADINGS } from "types/type";
 
@@ -28,6 +29,9 @@ export class RegisterService {
 		);
 		this.plugin.addCommand(increaseHeading.createCommand());
 		this.plugin.addCommand(decreaseHeading.createCommand());
+		this.plugin.addCommand(createInsertHeadingAtCurrentLevelCommand())
+		this.plugin.addCommand(createInsertHeadingAtDeeperLevelCommand())
+		this.plugin.addCommand(createInsertHeadingAtHigherLevelCommand())
 
 		this.plugin.registerEditorExtension(
 			Prec.highest(

src/utils/markdown.ts

@@ -62,3 +62,27 @@ export const getHeadingLines = (
 	}
 	return { headingLines, minHeading, maxHeading };
 };
+
+// goes backwards from the `from` line, returns line number of first line containing any heading
+export const getPreviousHeading = (
+	editor: {
+		getLine: (number: number) => string;
+	}, 
+	from: number 
+) => {
+
+	let fence: FenceType = null;
+	let start = from > 0 ? from - 1 : 0
+
+	for (let line = start; line >= 0; line--) {
+		fence = getFenceStatus(fence, checkFence(editor.getLine(line)));
+		if (fence) continue;
+
+		if (checkHeading(editor.getLine(line)) > 0) {
+			return line
+		}
+	}
+
+	// no heading found
+	return undefined
+};

test/utils.test.ts

@@ -5,6 +5,7 @@ import {
 	FenceType,
 	getFenceStatus,
 	getHeadingLines,
+	getPreviousHeading
 } from "utils/markdown";
 
 import { createRange } from "utils/range";
@@ -123,6 +124,62 @@ Normal
 	});
 });
 
+describe("getPreviousHeading", () => {
+	test("normal", () => {
+		const input = `# Heading1
+
+## Heading2
+
+Normal
+
+`;
+
+		const editor = new Editor(input);
+		expect(getPreviousHeading(editor, 4)).toEqual(2);
+	});
+
+	test("edge", () => {
+		const input = `# Heading1
+
+## Heading2
+
+Normal
+`;
+		const editor = new Editor(input);
+		expect(getPreviousHeading(editor, 1)).toEqual(0);
+	});
+
+	test("no heading", () => {
+		const input = `Normal
+
+Normal
+
+~~~~
+
+addAbortSignal
+
+~~~
+
+Normal
+
+`;
+
+		const editor = new Editor(input);
+		expect(getPreviousHeading(editor, 10)).toEqual(undefined);
+	});
+
+	test("'from line' contains heading", () => {
+		const input = `# Heading1
+
+## Heading2
+
+Normal
+	`;
+		const editor = new Editor(input);
+		expect(getPreviousHeading(editor, 2)).toEqual(0);
+	});
+});
+
 describe("compose editorChange", () => {
 	test("", () => {
 		const input = `a