fix: Support Excalidraw inside scrollable container (#3018)

* refactor: remove position fixed from excalidraw container, modal and stats

* remove unused css

* remove position fixed from toast and scroll to content

* Make excal interactable by fixing offsets and set popover as fixed since position needs to be calculate from viewport  top

* Assign 200px less than height of Excalidraw to the selected shapes actions o UI doesn't overflow

* update changelog, readme and package.json

src/components/App.tsx

@@ -51,6 +51,7 @@ import {
   LINE_CONFIRM_THRESHOLD,
   MIME_TYPES,
   POINTER_BUTTON,
+  SCROLL_TIMEOUT,
   TAP_TWICE_TIMEOUT,
   TEXT_TO_CENTER_SNAP_THRESHOLD,
   TOUCH_CTX_MENU_TIMEOUT,
@@ -825,6 +826,7 @@ class App extends React.Component<ExcalidrawProps, AppState> {
 
     document.addEventListener(EVENT.PASTE, this.pasteFromClipboard);
     document.addEventListener(EVENT.CUT, this.onCut);
+    document.addEventListener(EVENT.SCROLL, this.onScroll);
 
     window.addEventListener(EVENT.RESIZE, this.onResize, false);
     window.addEventListener(EVENT.UNLOAD, this.onUnload, false);
@@ -998,6 +1000,10 @@ class App extends React.Component<ExcalidrawProps, AppState> {
     }
   }
 
+  private onScroll = debounce(() => {
+    this.setState({ ...this.getCanvasOffsets() });
+  }, SCROLL_TIMEOUT);
+
   // Copy/paste
 
   private onCut = withBatchedUpdates((event: ClipboardEvent) => {

src/components/LayerUI.tsx

@@ -442,7 +442,15 @@ const LayerUI = ({
         "transition-left": zenModeEnabled,
       })}
     >
-      <Island className={CLASSES.SHAPE_ACTIONS_MENU} padding={2}>
+      <Island
+        className={CLASSES.SHAPE_ACTIONS_MENU}
+        padding={2}
+        style={{
+          // we want to make sure this doesn't overflow so substracting 200
+          // which is approximately height of zoom footer and top left menu items with some buffer
+          maxHeight: `${appState.height - 200}px`,
+        }}
+      >
         <SelectedShapeActions
           appState={appState}
           elements={elements}
@@ -603,18 +611,6 @@ const LayerUI = ({
       >
         {t("buttons.exitZenMode")}
       </button>
-      {appState.scrolledOutside && (
-        <button
-          className="scroll-back-to-content"
-          onClick={() => {
-            setAppState({
-              ...calculateScrollCenter(elements, appState, canvas),
-            });
-          }}
-        >
-          {t("buttons.scrollBackToContent")}
-        </button>
-      )}
     </footer>
   );
 
@@ -677,6 +673,18 @@ const LayerUI = ({
       {renderBottomAppMenu()}
       {renderGitHubCorner()}
       {renderFooter()}
+      {appState.scrolledOutside && (
+        <button
+          className="scroll-back-to-content"
+          onClick={() => {
+            setAppState({
+              ...calculateScrollCenter(elements, appState, canvas),
+            });
+          }}
+        >
+          {t("buttons.scrollBackToContent")}
+        </button>
+      )}
     </div>
   );
 };

src/components/Modal.scss

@@ -1,8 +1,13 @@
 @import "../css/variables.module";
 
 .excalidraw {
+  &.excalidraw-modal-container {
+    position: absolute;
+    z-index: 10;
+  }
+
   .Modal {
-    position: fixed;
+    position: absolute;
     top: 0;
     left: 0;
     right: 0;
@@ -15,7 +20,7 @@
   }
 
   .Modal__background {
-    position: fixed;
+    position: absolute;
     top: 0;
     left: 0;
     right: 0;
@@ -82,7 +87,7 @@
     }
 
     .Modal__content {
-      position: fixed;
+      position: absolute;
       top: 0;
       left: 0;
       right: 0;

src/components/Modal.tsx

@@ -54,7 +54,7 @@ const useBodyRoot = () => {
       ?.classList.contains("Appearance_dark");
     const div = document.createElement("div");
 
-    div.classList.add("excalidraw");
+    div.classList.add("excalidraw", "excalidraw-modal-container");
 
     if (isDarkTheme) {
       div.classList.add("Appearance_dark");

src/components/Popover.scss

@@ -1,14 +1,6 @@
 .excalidraw {
   .popover {
-    position: absolute;
+    position: fixed;
     z-index: 10;
   }
-
-  .popover .cover {
-    position: fixed;
-    top: 0;
-    left: 0;
-    right: 0;
-    bottom: 0;
-  }
 }

src/components/Stats.scss

@@ -1,7 +1,7 @@
 @import "../css/variables.module";
 
 .Stats {
-  position: fixed;
+  position: absolute;
   top: 64px;
   right: 12px;
   font-size: 12px;

src/components/Toast.scss

@@ -11,7 +11,7 @@
     left: 50%;
     margin-left: -150px;
     padding: 4px 0;
-    position: fixed;
+    position: absolute;
     text-align: center;
     width: 300px;
     z-index: 999999;