fix: Scroll to display contents elements. (#4519)

## Description

ref #3994

Scroll is seriously changed so need to be carefully tested.

As side effect this fixes "When clicking "Content Block" in the
navigator, nothing is scrolled into view."

`+` fixed: When inserting a template instance, it should be selected
automatically.


## Steps for reproduction

1. click button
2. expect xyz

## Code Review

- [ ] hi @kof, I need you to do
  - conceptual review (architecture, feature-correctness)
  - detailed review (read every line)
  - test it on preview

## Before requesting a review

- [ ] made a self-review
- [ ] added inline comments where things may be not obvious (the "why",
not "what")

## Before merging

- [ ] tested locally and on preview environment (preview dev login:
0000)
- [ ] updated [test
cases](https://github.com/webstudio-is/webstudio/blob/main/apps/builder/docs/test-cases.md)
document
- [ ] added tests
- [ ] if any new env variables are added, added them to `.env` file

apps/builder/app/builder/features/workspace/canvas-tools/outline/block-instance-outline.tsx

@@ -53,6 +53,7 @@ import {
 import { shallowEqual } from "shallow-equal";
 import { MetaIcon } from "~/builder/shared/meta-icon";
 import { skipInertHandlersAttribute } from "~/builder/shared/inert-handlers";
+import { selectInstance } from "~/shared/awareness";
 
 export const findBlockSelector = (
   anchor: InstanceSelector,
@@ -274,6 +275,8 @@ const TemplatesMenu = ({
                   { type: "id", value: newRootInstanceId },
                 ];
                 insertInstanceChildrenMutable(data, children, target);
+
+                selectInstance([newRootInstanceId, ...target.parentSelector]);
               });
             }}
           >

apps/builder/app/canvas/instance-selected.ts

@@ -123,10 +123,29 @@ const subscribeSelectedInstance = (
     selectedInstanceSelector
   );
 
-  visibleElements[0]?.scrollIntoView({
-    behavior: "smooth",
-    block: "nearest",
-  });
+  const updateScroll = () => {
+    const bbox = getAllElementsBoundingBox(visibleElements);
+
+    // Adds a small amount of space around the element after scrolling
+    const topScrollMargin = 16;
+
+    if (bbox.top < 0 || bbox.bottom > window.innerHeight) {
+      const moveToTopDelta = bbox.top - topScrollMargin;
+      const moveToBottomDelta =
+        bbox.bottom - window.innerHeight + topScrollMargin;
+
+      // scrollTo is used because scrollIntoView does not work with elements that have display:contents, etc.
+      // Here, we can be confident that if the outline can be calculated, we can scroll to it.
+      window.scrollTo({
+        top:
+          window.scrollY +
+          (Math.abs(moveToTopDelta) < Math.abs(moveToBottomDelta)
+            ? moveToTopDelta
+            : moveToBottomDelta),
+        behavior: "smooth",
+      });
+    }
+  };
 
   const updateElements = () => {
     visibleElements = getVisibleElementsByInstanceSelector(
@@ -236,6 +255,9 @@ const subscribeSelectedInstance = (
 
       // Having that elements can be changed (i.e. div => address tag change, observe again)
       updateObservers();
+
+      // update scroll state
+      updateScroll();
     });
   };