build method

  1. @override
Widget build(
  1. BuildContext context
)
override

Describes the part of the user interface represented by this widget.

The framework calls this method when this widget is inserted into the tree in a given BuildContext and when the dependencies of this widget change (e.g., an InheritedWidget referenced by this widget changes). This method can potentially be called in every frame and should not have any side effects beyond building a widget.

The framework replaces the subtree below this widget with the widget returned by this method, either by updating the existing subtree or by removing the subtree and inflating a new subtree, depending on whether the widget returned by this method can update the root of the existing subtree, as determined by calling Widget.canUpdate.

Typically implementations return a newly created constellation of widgets that are configured with information from this widget's constructor and from the given BuildContext.

The given BuildContext contains information about the location in the tree at which this widget is being built. For example, the context provides the set of inherited widgets for this location in the tree. A given widget might be built with multiple different BuildContext arguments over time if the widget is moved around the tree or if the widget is inserted into the tree in multiple places at once.

The implementation of this method must only depend on:

If a widget's build method is to depend on anything else, use a StatefulWidget instead.

See also:

  • StatelessWidget, which contains the discussion on performance considerations.

Implementation

@override
Widget build(BuildContext context) {
  String currDateStr = '';
  Map noteContent = {};

  if (prevNoteData == null) {
    // New note: fetch current date for heading
    currDateStr =
        DateFormat('dd MMMM yyyy').format(DateTime.now()).toString();
  } else {
    // Editing existing note (shared/unshared): extract content
    if (shared) {
      noteContent = prevNoteData!['sharedNoteContent'];
      // noteInfo = prevNoteData!['sharedNoteInfo'];
    } else {
      noteContent = prevNoteData as Map<dynamic, dynamic>;
    }
  }

  Row noteEditActionBar() {
    return Row(
      mainAxisAlignment: MainAxisAlignment.end,
      children: (prevNoteData == null)
          // New Note: save button only
          ? [
              NoteSaveButton(
                textController: _textController!,
                formKey: formKey,
                shared: shared,
                notesMap: notesMap,
              ),
            ]
          : [
              // Edit Note: save and back buttons
              NoteSaveButton(
                textController: _textController!,
                formKey: formKey,
                prevNoteData: prevNoteData,
                shared: shared,
                notesMap: notesMap,
              ),
              const SizedBox(
                width: 5,
              ),
              // Nav to view note or view shared note
              (shared)
                  ? NoteBackButton(
                      childPage:
                          ViewSharedNoteScreen(sharedNoteData: noteInfo),
                    )
                  : NoteBackButton(
                      childPage: ViewNote(
                        noteData: prevNoteData as Map<dynamic, dynamic>,
                        notesMap: notesMap,
                      ),
                    ),
            ],
    );
  }

  return Column(
    mainAxisSize: MainAxisSize.min,
    children: [
      Flexible(
        fit: FlexFit.loose,
        child: SingleChildScrollView(
          child: Column(
            children: [
              const SizedBox(
                height: 10,
              ),
              Padding(
                padding: const EdgeInsets.all(10.0),
                child: FormBuilder(
                  key: formKey,
                  onChanged: () {
                    formKey.currentState!.save();
                  },
                  autovalidateMode: AutovalidateMode.disabled,
                  skipDisabled: true,
                  child: Column(
                    children: [
                      // New note: show current date
                      if (prevNoteData == null) ...[
                        Row(
                          crossAxisAlignment: CrossAxisAlignment.start,
                          children: [
                            Text(
                              'Date: $currDateStr',
                              style: titleStyle,
                            ),
                          ],
                        ),
                        const SizedBox(
                          height: 10,
                        ),
                      ],
                      // Edit existing note: populated text field with
                      // previous note data
                      FormBuilderTextField(
                        name: noteTitlePred,
                        initialValue: (prevNoteData != null)
                            ? noteContent[noteTitlePred]
                            : null,
                        // Initial focus in title field
                        autofocus: true,
                        focusNode: _focusTitle,
                        decoration: const InputDecoration(
                          labelText: 'Note Title',
                          labelStyle: TextStyle(
                            color: darkBlue,
                            letterSpacing: 1.5,
                            fontSize: 13.0,
                            fontWeight: FontWeight.bold,
                          ),
                          //errorText: 'error',
                        ),
                        validator: FormBuilderValidators.compose([
                          FormBuilderValidators.required(),
                        ]),
                      ),
                    ],
                  ),
                ),
              ),
              const SizedBox(
                height: 10,
              ),
              markdownEditor(context, _textController!, _focusContent, data),
              const SizedBox(
                height: 20,
              ),
            ],
          ),
        ),
      ),
      // Action buttons - always visible
      Column(
        children: <Widget>[
          Container(
            padding: const EdgeInsets.only(left: 20, right: 20),
            child: noteEditActionBar(),
          ),
          const SizedBox(
            height: 10,
          ),
        ],
      ),
    ],
  );
}