ClipRRect and ClipPath in Flutter - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a rounded rectangle clip with a radius of 10.

Flutter

ClipRRect(
  borderRadius: BorderRadius.circular([1]),
  child: Container(color: Colors.blue, width: 100, height: 100),
)

Drag options to blanks, or click blank then click option'

A10

B20

C5

D15

Attempts:

3 left

💡 Hint

Common Mistakes

Using a very large number makes corners too round.

Forgetting to wrap the child widget.

The BorderRadius.circular method takes a radius value. Here, 10 creates a smooth rounded corner.

2fill in blank

medium

Complete the code to clip a widget with a circular shape using ClipPath.

Flutter

ClipPath(
  clipper: CircleClipper(),
  child: Container(color: Colors.red, width: 100, height: 100),
);

class CircleClipper extends CustomClipper<Path> {
  @override
  Path getClip(Size size) {
    return Path()..addOval(Rect.fromCircle(center: Offset(size.width / 2, size.height / 2), radius: [1]));
  }

  @override
  bool shouldReclip(CustomClipper<Path> oldClipper) => false;
}

Drag options to blanks, or click blank then click option'

Asize.width

Bsize.width / 4

Csize.height

Dsize.width / 2

Attempts:

3 left

💡 Hint

Common Mistakes

Using the full width or height causes clipping outside the widget.

Using a quarter radius makes the circle too small.

The radius for a circle clip should be half the width to fit perfectly inside the widget.

3fill in blank

hard

Fix the error in the ClipRRect code to properly clip the child widget.

Flutter

ClipRRect(
  borderRadius: BorderRadius.circular(20),
  child: [1](color: Colors.green, width: 150, height: 150),
)

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AContainer

BText

CRow

DColumn

Attempts:

3 left

💡 Hint

Common Mistakes

Using Text without background color.

Using layout widgets without visible background.

The child of ClipRRect should be a widget that can have size and color, like Container. Text or layout widgets alone won't show the clipping effect clearly.

4fill in blank

hard

Fill both blanks to create a ClipPath that clips a triangle shape.

Flutter

ClipPath(
  clipper: [1](),
  child: Container(color: Colors.orange, width: 120, height: 120),
);

class [2] extends CustomClipper<Path> {
  @override
  Path getClip(Size size) {
    Path path = Path();
    path.moveTo(size.width / 2, 0);
    path.lineTo(0, size.height);
    path.lineTo(size.width, size.height);
    path.close();
    return path;
  }

  @override
  bool shouldReclip(CustomClipper<Path> oldClipper) => false;
}

Drag options to blanks, or click blank then click option'

ATriangleClipper

BCircleClipper

CSquareClipper

DOvalClipper

Attempts:

3 left

💡 Hint

Common Mistakes

Mismatching class and instance names.

Using a clipper that clips a different shape.

The clipper class and its instance must have the same name. Here, TriangleClipper defines the triangle shape.

5fill in blank

hard

Fill all three blanks to create a ClipRRect with elliptical border radius on top corners only.

Flutter

ClipRRect(
  borderRadius: BorderRadius.only(
    topLeft: Radius.[1](x: 30, y: 50),
    topRight: Radius.[2](x: [3], y: 50),
  ),
  child: Container(color: Colors.purple, width: 200, height: 100),
)

Drag options to blanks, or click blank then click option'

Aelliptical

Bcircular

C40

D50

Attempts:

3 left

💡 Hint

Common Mistakes

Using Radius.circular instead of elliptical.

Using same x values for both corners.

Forgetting to specify y values.

Use Radius.elliptical to create elliptical corners. The x and y values define the ellipse radii. Here, top corners have elliptical radius with x=30 and x=40 respectively.

Practice

1. What is the main purpose of the ClipRRect widget in Flutter?

easy

A. To add padding around a widget

B. To clip a widget with a custom path shape

C. To animate a widget's size

D. To clip a widget with rounded rectangle corners

Solution

1. Step 1: Understand ClipRRect usage

   The ClipRRect widget clips its child using a rounded rectangle shape.

2. Step 2: Compare with other options

   ClipPath clips with custom shapes, padding adds space, animation changes size.

3. Final Answer:

   To clip a widget with rounded rectangle corners -> Option D

4. Quick Check:

   ClipRRect = Rounded rectangle clip [OK]

Hint: ClipRRect always clips with rounded rectangles [OK]

Common Mistakes:

• Confusing ClipRRect with ClipPath
• Thinking ClipRRect adds padding
• Assuming ClipRRect animates widgets

2. Which of the following is the correct syntax to clip a widget with rounded corners using ClipRRect?

easy

A. ClipRRect(borderRadius: BorderRadius.circular(10), child: Text('Hello'))

B. ClipRRect(radius: 10, child: Text('Hello'))

C. ClipRRect(cornerRadius: 10, child: Text('Hello'))

D. ClipRRect(borderRadius: 10, child: Text('Hello'))

Solution

1. Step 1: Recall ClipRRect property names

   The correct property for rounded corners is borderRadius with a BorderRadius.circular() value.

2. Step 2: Check syntax correctness

   ClipRRect(borderRadius: BorderRadius.circular(10), child: Text('Hello')) uses correct property and value type; others use wrong property names or types.

3. Final Answer:

   ClipRRect(borderRadius: BorderRadius.circular(10), child: Text('Hello')) -> Option A

4. Quick Check:

   borderRadius with BorderRadius.circular() is correct [OK]

Hint: Use borderRadius: BorderRadius.circular() for ClipRRect [OK]

Common Mistakes:

• Using radius or cornerRadius instead of borderRadius
• Passing integer directly instead of BorderRadius.circular()
• Omitting the child widget

3. What will be the visual result of this Flutter code snippet?

ClipRRect(
  borderRadius: BorderRadius.circular(20),
  child: Container(
    width: 100,
    height: 100,
    color: Colors.blue,
  ),
)

medium

A. A blue square with rounded corners of radius 20

B. A blue square with sharp corners

C. A blue circle with radius 20

D. A blue rectangle with no clipping

Solution

1. Step 1: Analyze ClipRRect effect

   The ClipRRect clips the child container with rounded corners of radius 20.

2. Step 2: Understand container shape

   The container is a 100x100 square colored blue, so clipping rounds its corners.

3. Final Answer:

   A blue square with rounded corners of radius 20 -> Option A

4. Quick Check:

   ClipRRect rounds corners = blue square with rounded corners [OK]

Hint: ClipRRect rounds corners, does not make circles [OK]

Common Mistakes:

• Thinking ClipRRect creates circles
• Ignoring borderRadius effect
• Assuming no clipping happens

4. Identify the error in this Flutter code using ClipPath:

ClipPath(
  clipper: CustomClipper(),
  child: Container(color: Colors.red, width: 100, height: 100),
)

medium

A. Container cannot be a child of ClipPath

B. clipper property should be a Widget, not a CustomClipper

C. CustomClipper is an abstract class and cannot be used directly

D. Colors.red is not a valid color

Solution

1. Step 1: Understand CustomClipper usage

   CustomClipper is an abstract class; you must create a subclass implementing its methods.

2. Step 2: Check clipper property type

   The clipper property requires an instance of a subclass of CustomClipper, not the abstract class itself.

3. Final Answer:

   CustomClipper is an abstract class and cannot be used directly -> Option C

4. Quick Check:

   CustomClipper must be subclassed before use [OK]

Hint: CustomClipper must be subclassed, not used directly [OK]

Common Mistakes:

• Using CustomClipper directly without subclassing
• Confusing clipper property type
• Thinking Container can't be child

5. You want to clip a widget into a triangle shape using Flutter. Which approach correctly uses ClipPath to achieve this?

hard

A. Use ClipRRect with borderRadius set to 0

B. Use ClipPath with a CustomClipper that defines a triangle path

C. Use ClipOval with a rectangular child

D. Use Container with padding and background color

Solution

1. Step 1: Understand ClipPath flexibility

   ClipPath allows clipping with any shape by defining a custom path in a subclass of CustomClipper.

2. Step 2: Identify correct method for triangle shape

   To clip a triangle, you must create a CustomClipper that draws a triangle path and pass it to ClipPath.

3. Step 3: Eliminate incorrect options

   ClipRRect only clips rounded rectangles, ClipOval clips ovals/circles, and Container does not clip shapes.

4. Final Answer:

   Use ClipPath with a CustomClipper that defines a triangle path -> Option B

5. Quick Check:

   ClipPath + CustomClipper = any shape clip [OK]

Hint: ClipPath + CustomClipper = clip any shape [OK]

Common Mistakes:

• Trying to clip triangle with ClipRRect
• Using ClipOval for non-oval shapes
• Confusing padding with clipping