title: Flutter web, stack with icon and number
body: <p>I am a beginner in flutter, I have a problem with my web application.</p>
  
  <p>I want to use the stack widget but sometimes the stack does not work well.
  I want to dispaly an icon with a number above.</p>
  
  <p>When i refresh the browser, sometimes the number goes under, sometimes that works well.
  Maybe the icon take time to load. Do you have any idea how to resolve my problem ?</p>
  
  <p><strong>Error Image</strong></p>
  
  <p><img src="https://i.stack.imgur.com/QsEt5.png" alt="error image"> </p>
  
  <p><strong>Normal Image</strong></p>
  
  <p><img src="https://i.stack.imgur.com/NJO0H.png" alt="normal image"></p>
  
  <pre><code>child: Row(
              children: &lt;Widget&gt;[
                Visibility(
                  visible: nb != 0,
                  child: Stack(
                    overflow: Overflow.visible,
                    children: &lt;Widget&gt;[
                      Icon(
                        Icons.description,
                        color: AppColors.lightGrey,
                        size: AppSizes.xl,
                      ),
                      Positioned(
                        top: -5.0,
                        left: -5.0,
                        child: Container(
                          padding: const EdgeInsets.all(
                            AppSizes.size0,
                          ),
                          decoration: const BoxDecoration(
                            color: AppColors.red,
                            shape: BoxShape.circle,
                          ),
                          child: Text(
                            nb.toString(),
                            style: const TextStyle(
                              color: Colors.white,
                              fontSize: 10.0,
                            ),
                          ),
                        ),
                      )
                    ],
                  ),
                ),
                const SizedBox(width: AppSizes.lg),
                Visibility(
                  visible: nb2 != 0,
                  child: Stack(
                    overflow: Overflow.visible,
                    children: &lt;Widget&gt;[
                      Icon(
                        Icons.info_outline,
                        color: AppColors.lightGrey,
                        size: AppSizes.xl,
                      ),
                      Positioned(
                        top: -5.0,
                        left: -5.0,
                        child: Container(
                          padding: const EdgeInsets.all(
                            AppSizes.size0,
                          ),
                          decoration: const BoxDecoration(
                            color: AppColors.blue,
                            shape: BoxShape.circle,
                          ),
                          child: Text(
                            nb2.toString(),
                            style: const TextStyle(
                              color: Colors.white,
                              fontSize: 10.0,
                            ),
                          ),
                        ),
                      )
                    ],
                  ),
                ),
              ],
            )
  </code></pre>