Responsive layout patterns in Flutter - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a responsive layout that uses a Column on small screens.

Flutter

Widget build(BuildContext context) {
  return LayoutBuilder(
    builder: (context, constraints) {
      if (constraints.maxWidth < 600) {
        return [1](
          children: [Text('Small screen')],
        );
      } else {
        return Row(
          children: [Text('Large screen')],
        );
      }
    },
  );
}

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

AColumn

BRow

CContainer

DStack

Attempts:

3 left

💡 Hint

Common Mistakes

Using Row instead of Column for small screens.

Using Container which does not arrange children.

On small screens, a Column arranges children vertically, which is suitable for narrow widths.

2fill in blank

medium

Complete the code to use MediaQuery to get the screen width.

Flutter

double screenWidth = MediaQuery.of(context).[1].width;

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

Awidget

Bsize

Ctext

Dpadding

Attempts:

3 left

💡 Hint

Common Mistakes

Using MediaQuery.of(context).data which is invalid.

Using MediaQuery.of(context).text which does not exist.

MediaQuery.of(context).size.width provides access to screen size and other info.

3fill in blank

hard

Fix the error in the code to make the layout responsive using Flex widget.

Flutter

return Flex(
  direction: [1],
  children: [Text('Responsive')],
);

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

ADirection.horizontal

BAxis.horizontal

CAxis.vertical

DDirection.vertical

Attempts:

3 left

💡 Hint

Common Mistakes

Using Direction instead of Axis enum.

Using Axis.horizontal when vertical layout is needed.

Flex widget uses Axis.vertical or Axis.horizontal to set direction. Axis.vertical stacks children vertically.

4fill in blank

hard

Fill both blanks to create a responsive layout that switches between Row and Column based on width.

Flutter

Widget build(BuildContext context) {
  return LayoutBuilder(
    builder: (context, constraints) {
      return [1](
        direction: constraints.maxWidth > 500 ? [2] : Axis.vertical,
        children: [Text('Responsive layout')],
      );
    },
  );
}

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

AFlex

BRow

CAxis.horizontal

DColumn

Attempts:

3 left

💡 Hint

Common Mistakes

Using Row widget directly without direction property.

Using Column widget where direction property is needed.

Flex widget with direction Axis.horizontal creates a Row-like layout; Axis.vertical creates a Column-like layout.

5fill in blank

hard

Fill all three blanks to create a responsive GridView with 2 columns on small screens and 4 on large screens.

Flutter

GridView.count(
  crossAxisCount: constraints.maxWidth < 600 ? [1] : [2],
  children: List.generate(8, (index) => [3]),
);

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

A2

B4

CCard(child: Text('Item $index'))

DContainer()

Attempts:

3 left

💡 Hint

Common Mistakes

Using fixed column count ignoring screen width.

Using Container() which shows empty boxes.

Use 2 columns for narrow screens, 4 for wide. Each grid item is a Card with text showing the index.

Practice

1. What is the main purpose of using responsive layout patterns in Flutter apps?

easy

A. To make the app look good on different screen sizes

B. To add animations to the app

C. To improve app performance by caching data

D. To change the app's theme colors automatically

Solution

1. Step 1: Understand responsive layout meaning

   Responsive layouts adjust UI to fit various screen sizes and orientations.

2. Step 2: Identify the main goal

   The goal is to ensure the app looks good and works well on phones, tablets, and other devices.

3. Final Answer:

   To make the app look good on different screen sizes -> Option A

4. Quick Check:

   Responsive layout = good appearance on all screens [OK]

Hint: Responsive means adapting UI to screen size [OK]

Common Mistakes:

• Confusing responsive layout with animations
• Thinking it improves performance directly
• Mixing it with theme or color changes

2. Which Flutter widget helps you get the current screen size inside its builder function?

easy

A. Container

B. MediaQuery

C. LayoutBuilder

D. Scaffold

Solution

1. Step 1: Recall widgets for screen size

   MediaQuery provides screen info globally, but LayoutBuilder gives constraints inside its builder.

2. Step 2: Identify widget with builder function

   LayoutBuilder has a builder that provides BoxConstraints with maxWidth and maxHeight.

3. Final Answer:

   LayoutBuilder -> Option C

4. Quick Check:

   LayoutBuilder = widget with builder for size [OK]

Hint: LayoutBuilder uses builder with constraints [OK]

Common Mistakes:

• Choosing MediaQuery which is not a builder widget
• Picking Container or Scaffold which don't provide size info
• Confusing MediaQuery and LayoutBuilder roles

3. Given this Flutter code snippet, what widget will be shown on a screen width of 500 pixels?

LayoutBuilder(
  builder: (context, constraints) {
    if (constraints.maxWidth > 600) {
      return Text('Large Screen');
    } else {
      return Text('Small Screen');
    }
  },
)

medium

A. Text widget showing 'Small Screen'

B. Text widget showing 'Large Screen'

C. An error because maxWidth is not accessible

D. Empty container with no text

Solution

1. Step 1: Check the condition with maxWidth

   The code checks if maxWidth > 600 to show 'Large Screen'.

2. Step 2: Compare given width 500 with 600

   Since 500 is less than 600, the else branch runs, showing 'Small Screen'.

3. Final Answer:

   Text widget showing 'Small Screen' -> Option A

4. Quick Check:

   500 < 600 means 'Small Screen' shown [OK]

Hint: Compare maxWidth to 600 to pick text [OK]

Common Mistakes:

• Assuming 500 is greater than 600
• Thinking maxWidth is not accessible
• Ignoring else branch

4. What is wrong with this Flutter code for responsive layout?

LayoutBuilder(
  builder: (context, constraints) {
    if (constraints.maxWidth < 600) {
      return Row(children: [Text('A'), Text('B')]);
    } else {
      return Column(children: [Text('A'), Text('B')]);
    }
  },
)

medium

A. Row and Column are used incorrectly for screen sizes

B. Using Row for small screens may cause overflow horizontally

C. No error; code works fine for responsive layout

D. Missing MediaQuery to get screen size

Solution

1. Step 1: Analyze layout for small screens

   For small screens, a Row with two Text widgets may overflow horizontally.

2. Step 2: Understand overflow risk

   Row arranges children horizontally, which can cause overflow if width is limited.

3. Step 3: Check other options

   MediaQuery is not required here; LayoutBuilder provides constraints. Using Column on large screens is fine.

4. Final Answer:

   Using Row for small screens may cause overflow horizontally -> Option B

5. Quick Check:

   Row on narrow screen risks overflow [OK]

Hint: Row on narrow screen can overflow horizontally [OK]

Common Mistakes:

• Thinking code has no error
• Believing MediaQuery is mandatory here
• Confusing Row and Column usage

5. You want to create a responsive Flutter layout that shows a vertical list on narrow screens and a grid with 3 columns on wide screens. Which approach is best?

hard

A. Use a fixed Container size and ignore screen width

B. Use MediaQuery to get screen height and switch between ListView and GridView

C. Always use GridView with 3 columns regardless of screen size

D. Use LayoutBuilder to check maxWidth and return ListView or GridView accordingly

Solution

1. Step 1: Decide how to detect screen width

   LayoutBuilder provides maxWidth constraints inside builder, ideal for responsive layout.

2. Step 2: Choose widgets based on width

   Return ListView for narrow screens and GridView with 3 columns for wide screens.

3. Step 3: Evaluate other options

   MediaQuery height is not relevant; fixed Container ignores responsiveness; always GridView ignores narrow screens.

4. Final Answer:

   Use LayoutBuilder to check maxWidth and return ListView or GridView accordingly -> Option D

5. Quick Check:

   LayoutBuilder + conditional widgets = responsive layout [OK]

Hint: Use LayoutBuilder to switch layouts by width [OK]

Common Mistakes:

• Using screen height instead of width
• Ignoring responsiveness by fixed sizes
• Always using one layout without condition