1 files changed, 99 insertions, 0 deletions
diff --git a/packages/excalidraw/components/Stats/FontSize.tsx b/packages/excalidraw/components/Stats/FontSize.tsx
new file mode 100644
index 0000000..13dc6db
--- /dev/null
+++ b/packages/excalidraw/components/Stats/FontSize.tsx
@@ -0,0 +1,99 @@
+import type {
+  ExcalidrawElement,
+  ExcalidrawTextElement,
+} from "../../element/types";
+import StatsDragInput from "./DragInput";
+import type { DragInputCallbackType } from "./DragInput";
+import { mutateElement } from "../../element/mutateElement";
+import { getStepSizedValue } from "./utils";
+import { fontSizeIcon } from "../icons";
+import type Scene from "../../scene/Scene";
+import type { AppState } from "../../types";
+import { isTextElement, redrawTextBoundingBox } from "../../element";
+import { hasBoundTextElement } from "../../element/typeChecks";
+import { getBoundTextElement } from "../../element/textElement";
+
+interface FontSizeProps {
+  element: ExcalidrawElement;
+  scene: Scene;
+  appState: AppState;
+  property: "fontSize";
+}
+
+const MIN_FONT_SIZE = 4;
+const STEP_SIZE = 4;
+
+const handleFontSizeChange: DragInputCallbackType<
+  FontSizeProps["property"],
+  ExcalidrawTextElement
+> = ({
+  accumulatedChange,
+  originalElements,
+  shouldChangeByStepSize,
+  nextValue,
+  scene,
+}) => {
+  const elementsMap = scene.getNonDeletedElementsMap();
+
+  const origElement = originalElements[0];
+  if (origElement) {
+    const latestElement = elementsMap.get(origElement.id);
+    if (!latestElement || !isTextElement(latestElement)) {
+      return;
+    }
+
+    let nextFontSize;
+
+    if (nextValue !== undefined) {
+      nextFontSize = Math.max(Math.round(nextValue), MIN_FONT_SIZE);
+    } else if (origElement.type === "text") {
+      const originalFontSize = Math.round(origElement.fontSize);
+      const changeInFontSize = Math.round(accumulatedChange);
+      nextFontSize = Math.max(
+        originalFontSize + changeInFontSize,
+        MIN_FONT_SIZE,
+      );
+      if (shouldChangeByStepSize) {
+        nextFontSize = getStepSizedValue(nextFontSize, STEP_SIZE);
+      }
+    }
+
+    if (nextFontSize) {
+      mutateElement(latestElement, {
+        fontSize: nextFontSize,
+      });
+      redrawTextBoundingBox(
+        latestElement,
+        scene.getContainerElement(latestElement),
+        scene.getNonDeletedElementsMap(),
+      );
+    }
+  }
+};
+
+const FontSize = ({ element, scene, appState, property }: FontSizeProps) => {
+  const _element = isTextElement(element)
+    ? element
+    : hasBoundTextElement(element)
+    ? getBoundTextElement(element, scene.getNonDeletedElementsMap())
+    : null;
+
+  if (!_element) {
+    return null;
+  }
+
+  return (
+    <StatsDragInput
+      label="F"
+      value={Math.round(_element.fontSize * 10) / 10}
+      elements={[_element]}
+      dragInputCallback={handleFontSizeChange}
+      icon={fontSizeIcon}
+      appState={appState}
+      scene={scene}
+      property={property}
+    />
+  );
+};
+
+export default FontSize;