add core extensions

packages/core/src/extensions/focus.ts

@@ -0,0 +1,67 @@
+import { TextSelection } from 'prosemirror-state'
+import { Editor, Command } from '../Editor'
+import { createExtension } from '../Extension'
+import minMax from '../utils/minMax'
+
+type Position = 'start' | 'end' | number | boolean | null
+
+interface ResolvedSelection {
+  from: number,
+  to: number,
+}
+
+function resolveSelection(editor: Editor, position: Position = null): ResolvedSelection {
+  if (position === null) {
+    return editor.selection
+  }
+
+  if (position === 'start' || position === true) {
+    return {
+      from: 0,
+      to: 0,
+    }
+  }
+
+  if (position === 'end') {
+    const { size } = editor.state.doc.content
+
+    return {
+      from: size,
+      to: size - 1, // TODO: -1 only for nodes with content
+    }
+  }
+
+  return {
+    from: position as number,
+    to: position as number,
+  }
+}
+
+export const Focus = createExtension({
+  addCommands() {
+    return {
+      focus: (position: Position = null): Command => ({ editor, view, tr }) => {
+        if ((view.hasFocus() && position === null) || position === false) {
+          return true
+        }
+
+        const { from, to } = resolveSelection(editor, position)
+        const { doc } = tr
+        const resolvedFrom = minMax(from, 0, doc.content.size)
+        const resolvedEnd = minMax(to, 0, doc.content.size)
+        const selection = TextSelection.create(doc, resolvedFrom, resolvedEnd)
+
+        tr.setSelection(selection)
+        view.focus()
+
+        return true
+      },
+    }
+  },
+})
+
+declare module '../Editor' {
+  interface AllExtensions {
+    Focus: typeof Focus,
+  }
+}