ListView.builder do not automaticly add pages when overflow

[MichelMelhem]

Describe the bug
Hello,
When I use the widget ListView.builder and I have a problem. When the number of items in the list is greater than what the page can contain, the list is cut and the pdf ends. No new elements are automatically created to allow the remaining elements to be drawn.

To Reproduce
Code snippet to reproduce the behavior:

    return ui.Container(
                              alignment: ui.Alignment.topLeft,
                              child: ui.ListView.builder(
                                  itemCount: issues.length,
                                  itemBuilder: (ui.Context context, int index) {
                                    Issue issue = issues[index];
                                    return ui.Column(children: <ui.Widget>[
                                      ui.Header(
                                          text: "Issue n°${issue.id}",
                                          textStyle:
                                              ui.TextStyle(fontSize: 20)),
                                      ui.Text("Description :",
                                          textAlign: ui.TextAlign.left,
                                          style: ui.TextStyle(fontSize: 15)),
                                    
                                          })
                                    ]);
                                  }));
                        }));

This is an example but any list wich has a number of elements superior of what the page could render will do the job.
Expected behavior
The list is going to be cut and no new page will be created for rendering the rest of it.
Screenshots

Flutter Doctor

[√] Flutter (Channel stable, v1.9.1+hotfix.5, on Microsoft Windows [Version 10.0.18362.418], locale en-US)
    • Flutter version 1.9.1+hotfix.5 at C:\src\flutter
    • Framework revision 1aedbb1835 (2 days ago), 2019-10-17 08:37:27 -0700
    • Engine revision b863200c37
    • Dart version 2.5.0


[√] Android toolchain - develop for Android devices (Android SDK version 28.0.3)
    • Android SDK at C:\Users\Michel\AppData\Local\Android\Sdk
    • Android NDK location not configured (optional; useful for native profiling support)
    • Platform android-29, build-tools 28.0.3
    • ANDROID_HOME = C:\Users\Michel\AppData\Local\Android\Sdk
    • Java binary at: C:\Users\Michel\AppData\Local\JetBrains\Toolbox\apps\AndroidStudio\ch-1\191.5791312\jre\bin\java
    • Java version OpenJDK Runtime Environment (build 1.8.0_202-release-1483-b03)
    • All Android licenses accepted.

[!] Android Studio (version 3.4)
    • Android Studio at C:\Users\Michel\AppData\Local\JetBrains\Toolbox\apps\AndroidStudio\ch-0\182.5314842
    • Flutter plugin version 38.2.1
    • Dart plugin version 183.6270
    X Unable to determine bundled Java version.
    • Try updating or re-installing Android Studio.

[√] Android Studio (version 3.5)
    • Android Studio at C:\Users\Michel\AppData\Local\JetBrains\Toolbox\apps\AndroidStudio\ch-1\191.5791312
    • Flutter plugin version 38.2.3
    • Dart plugin version 191.8423
    • Java version OpenJDK Runtime Environment (build 1.8.0_202-release-1483-b03)

[√] VS Code (version 1.39.2)
    • VS Code at C:\Users\Michel\AppData\Local\Programs\Microsoft VS Code
    • Flutter extension version 3.5.1

[!] Connected device
    ! No devices available

! Doctor found issues in 2 categories.

Desktop (please complete the following information):

• [ 9] Android

Smartphone (please complete the following information):

• Device: Mi mix 3
• OS: Android 9
• Browser no web
• Version the latest version

[DavBfr]

First, if you use MultiPage, the widget that can create new pages must be the top level.
Then the only widgets that can create pages are Table, GridView, and Wrap.
"Wrap" is the most powerful, I would do like this:

    pdf.addPage(
      MultiPage(
        build: (Context context) => <Widget>[
          Wrap(
            children: List<Widget>.generate(issues.length, (int index) {
              final issue = issues[index];
              return Container(
                child: Column(
                  children: <Widget>[
                    Header(
                        text: "Issue n°${issue.id}",
                        textStyle: TextStyle(fontSize: 20)),
                    Text("Description :",
                        textAlign: TextAlign.left,
                        style: TextStyle(fontSize: 15)),
                  ],
                ),
              );
            }),
          ),
        ],
      ),
    );

[MichelMelhem]

Thank you !

[MichelMelhem]

Despite the very good solution you gave me i'm still getting an issue :
The space between each elements is very big even if the space could feet one of the list elements :

[MichelMelhem]

@DavBfr Any updates ?

[DavBfr]

Can it really fit?

Try to enable the debug output, using the static variable:

Document.debug = true;

This will draw margins and widget limits like the flutter debug paint feature.

[MichelMelhem]

Here for example there would be the place fot draw on the next page the start of the observation 7 until Picture 0 for example

[DavBfr]

No, it's a full child of wrapper that has to fit. If you want to split anywhere, remove the Container and Column and add the content directly as children of Wrap.

The lib puts you in control to design beautiful pdf documents.

[MichelMelhem]

yes, but if i have multiples elements to put inside my wrap how can i do without using a column ?

[DavBfr]

final children = <Widget>[];

for (var item in items) {
children.add(Text('my title'));
children.add(Text('my content'));
children.add(Image(...));
}

pdf.addPage(
      MultiPage(
        build: (Context context) => <Widget>[
          Wrap(children: children),
          ),
        ],
      ),
    );

[MichelMelhem]

@DavBfr The problem with your solution is that my items or no longer alligned in colllumn they are in row. How i can fix that ?

[DavBfr]

you can force all widgets to occupy the full width, using a SizedBox for example:

children.add(SizedBox(width:double.infinity, child:Text('my title')));

[MichelMelhem]

Thank you for your help !