fix: ⚡ Optimize GetPosition class (#370)

Author: ujas-m-simformsolutions

CHANGELOG.md

@@ -1,6 +1,7 @@
 ## [2.0.4] (Un-Released)
 - Feature [#387](https://github.com/SimformSolutionsPvtLtd/flutter_showcaseview/issues/387) - Provided barrier click disable functionality for a particular showcase.
 - Fixed [#383](https://github.com/SimformSolutionsPvtLtd/flutter_showcaseview/issues/383) - Targeted widget focusing issue when we applying size constraint on root widget(MaterialApp).
+- Improved internal `findRenderObject` calls.
 
 ## [2.0.3]
 - Feature [#148](https://github.com/SimformSolutionsPvtLtd/flutter_showcaseview/issues/148) - Add feasibility to add `textDirection` of `title` and `description`.

lib/src/get_position.dart

@@ -20,105 +20,105 @@
  * SOFTWARE.
  */
 
+import 'dart:math';
+
 import 'package:flutter/material.dart';
 
 class GetPosition {
-  final GlobalKey? key;
-  final EdgeInsets padding;
-  final double? screenWidth;
-  final double? screenHeight;
-  final RenderObject? rootRenderObject;
-
   GetPosition({
-    this.key,
+    required this.key,
+    required this.screenWidth,
+    required this.screenHeight,
     this.padding = EdgeInsets.zero,
-    this.screenWidth,
-    this.screenHeight,
     this.rootRenderObject,
-  });
+  }) {
+    getRenderBox();
+  }
 
-  Rect getRect() {
-    final box = key!.currentContext!.findRenderObject() as RenderBox;
+  final GlobalKey key;
+  final EdgeInsets padding;
+  final double screenWidth;
+  final double screenHeight;
+  final RenderObject? rootRenderObject;
 
-    var boxOffset = box.localToGlobal(
-      const Offset(0.0, 0.0),
+  late final RenderBox? _box;
+  late final Offset? _boxOffset;
+
+  void getRenderBox() {
+    var renderBox = key.currentContext?.findRenderObject() as RenderBox?;
+
+    if (renderBox == null) return;
+
+    _box = renderBox;
+    _boxOffset = _box?.localToGlobal(
+      Offset.zero,
       ancestor: rootRenderObject,
     );
-    if (boxOffset.dx.isNaN || boxOffset.dy.isNaN) {
-      return const Rect.fromLTRB(0, 0, 0, 0);
-    }
-    final topLeft = box.size.topLeft(boxOffset);
-    final bottomRight = box.size.bottomRight(boxOffset);
+  }
+
+  bool _checkBoxOrOffsetIsNull({bool checkDy = false, bool checkDx = false}) {
+    return _box == null ||
+        _boxOffset == null ||
+        (checkDx && (_boxOffset?.dx.isNaN ?? true)) ||
+        (checkDy && (_boxOffset?.dy.isNaN ?? true));
+  }
 
+  Rect getRect() {
+    if (_checkBoxOrOffsetIsNull(checkDy: true, checkDx: true)) {
+      return Rect.zero;
+    }
+    final topLeft = _box!.size.topLeft(_boxOffset!);
+    final bottomRight = _box!.size.bottomRight(_boxOffset!);
+    final leftDx = topLeft.dx - padding.left;
+    final leftDy = topLeft.dy - padding.top;
     final rect = Rect.fromLTRB(
-      topLeft.dx - padding.left < 0 ? 0 : topLeft.dx - padding.left,
-      topLeft.dy - padding.top < 0 ? 0 : topLeft.dy - padding.top,
-      bottomRight.dx + padding.right > screenWidth!
-          ? screenWidth!
-          : bottomRight.dx + padding.right,
-      bottomRight.dy + padding.bottom > screenHeight!
-          ? screenHeight!
-          : bottomRight.dy + padding.bottom,
+      leftDx.clamp(0, leftDx),
+      leftDy.clamp(0, leftDy),
+      min(bottomRight.dx + padding.right, screenWidth),
+      min(bottomRight.dy + padding.bottom, screenHeight),
     );
     return rect;
   }
 
   ///Get the bottom position of the widget
   double getBottom() {
-    final box = key!.currentContext!.findRenderObject() as RenderBox;
-    final boxOffset = box.localToGlobal(
-      const Offset(0.0, 0.0),
-      ancestor: rootRenderObject,
-    );
-    if (boxOffset.dy.isNaN) return padding.bottom;
-    final bottomRight = box.size.bottomRight(boxOffset);
+    if (_checkBoxOrOffsetIsNull(checkDy: true)) {
+      return padding.bottom;
+    }
+    final bottomRight = _box!.size.bottomRight(_boxOffset!);
     return bottomRight.dy + padding.bottom;
   }
 
   ///Get the top position of the widget
   double getTop() {
-    final box = key!.currentContext!.findRenderObject() as RenderBox;
-    final boxOffset = box.localToGlobal(
-      const Offset(0.0, 0.0),
-      ancestor: rootRenderObject,
-    );
-    if (boxOffset.dy.isNaN) return 0 - padding.top;
-    final topLeft = box.size.topLeft(boxOffset);
+    if (_checkBoxOrOffsetIsNull(checkDy: true)) {
+      return -padding.top;
+    }
+    final topLeft = _box!.size.topLeft(_boxOffset!);
     return topLeft.dy - padding.top;
   }
 
   ///Get the left position of the widget
   double getLeft() {
-    final box = key!.currentContext!.findRenderObject() as RenderBox;
-    final boxOffset = box.localToGlobal(
-      const Offset(0.0, 0.0),
-      ancestor: rootRenderObject,
-    );
-    if (boxOffset.dx.isNaN) return 0 - padding.left;
-    final topLeft = box.size.topLeft(boxOffset);
+    if (_checkBoxOrOffsetIsNull(checkDx: true)) {
+      return -padding.left;
+    }
+    final topLeft = _box!.size.topLeft(_boxOffset!);
     return topLeft.dx - padding.left;
   }
 
   ///Get the right position of the widget
   double getRight() {
-    final box = key!.currentContext!.findRenderObject() as RenderBox;
-    final boxOffset = box.localToGlobal(
-      const Offset(0.0, 0.0),
-      ancestor: rootRenderObject,
-    );
-    if (boxOffset.dx.isNaN) return padding.right;
-    final bottomRight = box.size.bottomRight(
-      box.localToGlobal(
-        const Offset(0.0, 0.0),
-        ancestor: rootRenderObject,
-      ),
-    );
+    if (_checkBoxOrOffsetIsNull(checkDx: true)) {
+      return padding.right;
+    }
+    final bottomRight = _box!.size.bottomRight(_boxOffset!);
     return bottomRight.dx + padding.right;
   }
 
   double getHeight() => getBottom() - getTop();
 
   double getWidth() => getRight() - getLeft();
 
-  double getCenter() => (getLeft() + getRight()) / 2;
+  double getCenter() => (getLeft() + getRight()) * 0.5;
 }