WIP #224 Dynamic multi column view

lib/main.dart

@@ -25,6 +25,7 @@ import 'package:in_app_purchase/in_app_purchase.dart';
 import 'plugins/circular_slider/single_circular_slider.dart';
 import 'package:share/receive_share_state.dart';
 import 'package:share/share.dart';
+import 'plugins/DynamicMultiColumnLayout.dart';
 
 import 'utils/logger.dart';
 

lib/plugins/DynamicMultiColumnLayout.dart

@@ -0,0 +1,146 @@
+import 'package:flutter/material.dart';
+import 'package:flutter/rendering.dart';
+import 'dart:math' as math;
+
+class DynamicMultiColumnLayout extends MultiChildRenderObjectWidget {
+
+  final int minColumnWidth;
+
+  DynamicMultiColumnLayout({
+    Key key,
+    this.minColumnWidth: 350,
+    List<Widget> children = const <Widget>[],
+  }) : super(key: key, children: children);
+
+  @override
+  RenderCustomLayoutBox createRenderObject(BuildContext context) {
+    return RenderCustomLayoutBox(minColumnWidth: this.minColumnWidth);
+  }
+
+}
+
+class RenderCustomLayoutBox extends RenderBox
+    with ContainerRenderObjectMixin<RenderBox, CustomLayoutParentData>,
+        RenderBoxContainerDefaultsMixin<RenderBox, CustomLayoutParentData> {
+
+  final int minColumnWidth;
+
+  RenderCustomLayoutBox({
+    this.minColumnWidth,
+    List<RenderBox> children,
+  }) {
+    addAll(children);
+  }
+
+  @override
+  void setupParentData(RenderBox child) {
+    if (child.parentData is! CustomLayoutParentData) {
+      child.parentData = CustomLayoutParentData();
+    }
+  }
+
+  double _getIntrinsicHeight(double childSize(RenderBox child)) {
+    double inflexibleSpace = 0.0;
+    RenderBox child = firstChild;
+    while (child != null) {
+      inflexibleSpace += childSize(child);
+      final FlexParentData childParentData = child.parentData;
+      child = childParentData.nextSibling;
+    }
+    return inflexibleSpace;
+  }
+
+  double _getIntrinsicWidth(double childSize(RenderBox child)) {
+    double maxSpace = 0.0;
+    RenderBox child = firstChild;
+    while (child != null) {
+      maxSpace = math.max(maxSpace, childSize(child));
+      final FlexParentData childParentData = child.parentData;
+      child = childParentData.nextSibling;
+    }
+    return maxSpace;
+  }
+
+  @override
+  double computeMinIntrinsicWidth(double height) {
+    return _getIntrinsicWidth((RenderBox child) => child.getMinIntrinsicWidth(height));
+  }
+
+  @override
+  double computeMaxIntrinsicWidth(double height) {
+    return _getIntrinsicWidth((RenderBox child) => child.getMaxIntrinsicWidth(height));
+  }
+
+  @override
+  double computeMinIntrinsicHeight(double width) {
+    return _getIntrinsicHeight((RenderBox child) => child.getMinIntrinsicHeight(width));
+  }
+
+  @override
+  double computeMaxIntrinsicHeight(double width) {
+    return _getIntrinsicHeight((RenderBox child) => child.getMaxIntrinsicHeight(width));
+  }
+
+  @override
+  void performLayout() {
+    int columnsCount;
+    List<double> columnXPositions = [];
+    List<double> columnYPositions = [];
+    if (childCount == 0) {
+      size = constraints.biggest;
+      assert(size.isFinite);
+      return;
+    }
+
+    columnsCount = (constraints.maxWidth ~/ this.minColumnWidth);
+    double columnWidth = constraints.maxWidth / columnsCount;
+    double startY = 0;
+    for (int i =0; i < columnsCount; i++) {
+      columnXPositions.add(i*columnWidth);
+      columnYPositions.add(startY);
+    }
+    RenderBox child = firstChild;
+    while (child != null) {
+      final CustomLayoutParentData childParentData = child.parentData;
+
+      int columnToAdd = 0;
+      double minYPosition = columnYPositions[0];
+      for (int i=0; i<columnsCount; i++) {
+        if (columnYPositions[i] < minYPosition) {
+          minYPosition = columnYPositions[i];
+          columnToAdd = i;
+        }
+      }
+      child.layout(BoxConstraints.tightFor(width: columnWidth), parentUsesSize: true);
+      childParentData.offset = Offset(columnXPositions[columnToAdd], columnYPositions[columnToAdd]);
+      final Size newSize = child.size;
+      columnYPositions[columnToAdd] = minYPosition + newSize.height;
+
+      child = childParentData.nextSibling;
+    }
+
+    double width = constraints.maxWidth;
+    double height = 0;
+    for (int i=0; i<columnsCount; i++) {
+      if (columnYPositions[i] > height) {
+        height = columnYPositions[i];
+      }
+    }
+
+    size = Size(width, height);
+  }
+
+  @override
+  void paint(PaintingContext context, Offset offset) {
+    defaultPaint(context, offset);
+  }
+
+  @override
+  bool hitTestChildren(HitTestResult result, { Offset position }) {
+    return defaultHitTestChildren(result, position: position);
+  }
+}
+
+class CustomLayoutParentData extends ContainerBoxParentData<RenderBox> {
+
+}

lib/view.dart

@@ -31,6 +31,16 @@ class ViewWidgetState extends State<ViewWidget> {
         child: _buildPanelChild(context),
       );
     } else {
+      return ListView(
+          shrinkWrap: true,
+          padding: EdgeInsets.all(0),
+          children: <Widget>[
+            DynamicMultiColumnLayout(
+              minColumnWidth: Sizes.minViewColumnWidth,
+              children: _buildChildren(context),
+            )
+          ]
+      );
       return ListView(
         shrinkWrap: true,
         padding: EdgeInsets.all(0),
@@ -61,7 +71,7 @@ class ViewWidgetState extends State<ViewWidget> {
     List<Widget> result = [];
     int layoutChildId = 0;
 
-    if (widget.view.badges.isNotEmpty) {
+    /*if (widget.view.badges.isNotEmpty) {
       result.add(
           LayoutId(
             id: "badges",
@@ -73,15 +83,11 @@ class ViewWidgetState extends State<ViewWidget> {
             ),
           )
       );
-    }
+    }*/
     widget.view.cards.forEach((HACard card){
       result.add(
-          LayoutId(
-            id: 'card_$layoutChildId',
-            child: card.build(context),
-          )
+          card.build(context)
       );
-      layoutChildId += 1;
     });
 
     return result;

pubspec.lock

@@ -164,7 +164,7 @@ packages:
       name: flutter_webview_plugin
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.3.7"
+    version: "0.3.8"
   http:
     dependency: transitive
     description:
@@ -374,7 +374,7 @@ packages:
       name: url_launcher
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "5.1.2"
+    version: "5.1.3"
   uuid:
     dependency: transitive
     description: