In my app , i have used google maps.

I am trying to set my layout using stack widget.

using Stack widget it fills the google map on entire screen.

then at top, search bar is positioned.

below that search bar i want to show list view which will act as to be auto complete search for google places depending on user text.

the problem is when i add list view to layout it gives error.

This is the error:

```
I/flutter ( 6057): ══╡ EXCEPTION CAUGHT BY RENDERING LIBRARY ╞═════════════════════════════════════════════════════════
I/flutter ( 6057): The following assertion was thrown during performLayout():
I/flutter ( 6057): RenderFlex children have non-zero flex but incoming height constraints are unbounded.
I/flutter ( 6057): When a column is in a parent that does not provide a finite height constraint, for example if it is
I/flutter ( 6057): in a vertical scrollable, it will try to shrink-wrap its children along the vertical axis. Setting a
I/flutter ( 6057): flex on a child (e.g. using Expanded) indicates that the child is to expand to fill the remaining
I/flutter ( 6057): space in the vertical direction.
I/flutter ( 6057): These two directives are mutually exclusive. If a parent is to shrink-wrap its child, the child
I/flutter ( 6057): cannot simultaneously expand to fit its parent.
I/flutter ( 6057): Consider setting mainAxisSize to MainAxisSize.min and using FlexFit.loose fits for the flexible
I/flutter ( 6057): children (using Flexible rather than Expanded). This will allow the flexible children to size
I/flutter ( 6057): themselves to less than the infinite remaining space they would otherwise be forced to take, and
I/flutter ( 6057): then will cause the RenderFlex to shrink-wrap the children rather than expanding to fit the maximum
I/flutter ( 6057): constraints provided by the parent.
I/flutter ( 6057): If this message did not help you determine the problem, consider using debugDumpRenderTree():
I/flutter ( 6057):   https://flutter.dev/debugging/#rendering-layer
I/flutter ( 6057):   http://api.flutter.dev/flutter/rendering/debugDumpRenderTree.html
I/flutter ( 6057): The affected RenderFlex is:
I/flutter ( 6057):   RenderFlex#7c916 relayoutBoundary=up2 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE(creator: Column ← Positioned ← Stack ← _BodyBuilder ← MediaQuery ← LayoutId-[<_ScaffoldSlot.body>] ← CustomMultiChildLayout ← AnimatedBuilder ← DefaultTextStyle ← AnimatedDefaultTextStyle ← _InkFeatures-[GlobalKey#dd38c ink renderer] ← NotificationListener<LayoutChangedNotification> ← ⋯, parentData: top=200.0; offset=Offset(0.0, 0.0) (can use size), constraints: BoxConstraints(unconstrained), size: MISSING, direction: vertical, mainAxisAlignment: start, mainAxisSize: max, crossAxisAlignment: center, verticalDirection: down)
I/flutter ( 6057): The creator information is set to:
I/flutter ( 6057):   Column ← Positioned ← Stack ← _BodyBuilder ← MediaQuery ← LayoutId-[<_ScaffoldSlot.body>] ←
I/flutter ( 6057):   CustomMultiChildLayout ← AnimatedBuilder ← DefaultTextStyle ← AnimatedDefaultTextStyle ←
I/flutter ( 6057):   _InkFeatures-[GlobalKey#dd38c ink renderer] ← NotificationListener<LayoutChangedNotification> ← ⋯
I/flutter ( 6057): The nearest ancestor providing an unbounded width constraint is: RenderStack#cff5c relayoutBoundary=up1 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE:
I/flutter ( 6057):   creator: Stack ← _BodyBuilder ← MediaQuery ← LayoutId-[<_ScaffoldSlot.body>] ←
I/flutter ( 6057):     CustomMultiChildLayout ← AnimatedBuilder ← DefaultTextStyle ← AnimatedDefaultTextStyle ←
I/flutter ( 6057):     _InkFeatures-[GlobalKey#dd38c ink renderer] ← NotificationListener<LayoutChangedNotification> ←
I/flutter ( 6057):     PhysicalModel ← AnimatedPhysicalModel ← ⋯
I/flutter ( 6057):   parentData: offset=Offset(0.0, 0.0); id=_ScaffoldSlot.body (can use size)
I/flutter ( 6057):   constraints: BoxConstraints(0.0<=w<=392.7, 0.0<=h<=759.3)
I/flutter ( 6057):   size: Size(392.7, 759.3)
I/flutter ( 6057):   alignment: AlignmentDirectional.topStart
I/flutter ( 6057):   textDirection: ltr
I/flutter ( 6057):   fit: loose
I/flutter ( 6057):   overflow: clip
I/flutter ( 6057): See also: https://flutter.dev/layout/
I/flutter ( 6057): If none of the above helps enough to fix this problem, please don't hesitate to file a bug:
I/flutter ( 6057):   https://github.com/flutter/flutter/issues/new?template=BUG.md
I/flutter ( 6057): 
I/flutter ( 6057): The relevant error-causing widget was:
I/flutter ( 6057):   Column file:///E:/ARSALAN_STUFF/PROJECTS_Codegasm/googlemap/flutter_app/lib/main.dart:211:24
I/flutter ( 6057): 
I/flutter ( 6057): When the exception was thrown, this was the stack:
I/flutter ( 6057): #0      RenderFlex.performLayout.<anonymous closure> (package:flutter/src/rendering/flex.dart:693:11)
I/flutter ( 6057): #1      RenderFlex.performLayout (package:flutter/src/rendering/flex.dart:720:10)
I/flutter ( 6057): #2      RenderObject.layout (package:flutter/src/rendering/object.dart:1767:7)
I/flutter ( 6057): #3      RenderStack.layoutPositionedChild (package:flutter/src/rendering/stack.dart:487:11)
I/flutter ( 6057): #4      RenderStack.performLayout (package:flutter/src/rendering/stack.dart:583:30)
I/flutter ( 6057): #5      RenderObject.layout (package:flutter/src/rendering/object.dart:1767:7)
I/flutter ( 6057): #6      MultiChildLayoutDelegate.layoutChild (package:flutter/src/rendering/custom_layout.dart:171:11)
I/flutter ( 6057): #7      _ScaffoldLayout.performLayout (package:flutter/src/material/scaffold.dart:484:7)
I/flutter ( 6057): #8      MultiChildLayoutDelegate._callPerformLayout (package:flutter/src/rendering/custom_layout.dart:240:7)
I/flutter ( 6057): #9      RenderCustomMultiChildLayoutBox.performLayout (package:flutter/src/rendering/custom_layout.dart:399:14)
I/flutter ( 6057): #10     RenderObject.layout (package:flutter/src/rendering/object.dart:1767:7)
I/flutter ( 6057): #11     RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:111:13)
I/flutter ( 6057): #12     RenderObject.layout (package:flutter/src/rendering/object.dart:1767:7)
I/flutter ( 6057): #13     RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:111:13)
I/flutter ( 6057): #14     _RenderCustomClip.performLayout (package:flutter/src/rendering/proxy_box.dart:1248:11)
I/flutter ( 6057): #15     RenderObject.layout (package:flutter/src/rendering/object.dart:1767:7)
I/flutter ( 6057): #16     RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:111:13)
I/flutter ( 6057): #17     RenderObject.layout (package:flutter/src/rendering/object.dart:1767:7)
I/flutter ( 6057): #18     RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:111:13)
I/flutter ( 6057): #19     RenderObject.layout (package:flutter/src/rendering/object.dart:1767:7)
I/flutter ( 6057): #20     RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:111:13)
I/flutter ( 6057): #21     RenderObject.layout (package:flutter/src/rendering/object.dart:1767:7)
I/flutter ( 6057): #22     RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:111:13)
I/flutter ( 6057): #23     RenderObject.layout (package:flutter/src/rendering/object.dart:1767:7)
I/flutter ( 6057): #24     RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:111:13)
I/flutter ( 6057): #25     RenderObject.layout (package:flutter/src/rendering/object.dart:1767:7)
I/flutter ( 6057): #26     RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:111:13)
I/flutter ( 6057): #27     RenderObject.layout (package:flutter/src/rendering/object.dart:1767:7)
I/flutter ( 6057): #28     RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:111:13)
I/flutter ( 6057): #29     RenderObject.layout (package:flutter/src/rendering/object.dart:1767:7)
I/flutter ( 6057): #30     RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:111:13)
I/flutter ( 6057): #31     RenderOffstage.performLayout (package:flutter/src/rendering/proxy_box.dart:3225:13)
I/flutter ( 6057): #32     RenderObject.layout (package:flutter/src/rendering/object.dart:1767:7)
I/flutter ( 6057): #33     _RenderTheatre.performLayout (package:flutter/src/widgets/overlay.dart:700:15)
I/flutter ( 6057): #34     RenderObject.layout (package:flutter/src/rendering/object.dart:1767:7)
I/flutter ( 6057): #35     RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:111:13)
I/flutter ( 6057): #36     RenderObject.layout (package:flutter/src/rendering/object.dart:1767:7)
I/flutter ( 6057): #37     RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:111:13)
I/flutter ( 6057): #38     RenderObject.layout (package:flutter/src/rendering/object.dart:1767:7)
I/flutter ( 6057): #39     RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:111:13)
I/flutter ( 6057): #40     RenderObject.layout (package:flutter/src/rendering/object.dart:1767:7)
I/flutter ( 6057): #41     RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:111:13)
I/flutter ( 6057): #42     RenderObject.layout (package:flutter/src/rendering/object.dart:1767:7)
I/flutter ( 6057): #43     RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:111:13)
I/flutter ( 6057): #44     RenderObject.layout (package:flutter/src/rendering/object.dart:1767:7)
I/flutter ( 6057): #45     RenderView.performLayout (package:flutter/src/rendering/view.dart:167:13)
I/flutter ( 6057): #46     RenderObject._layoutWithoutResize (package:flutter/src/rendering/object.dart:1630:7)
I/flutter ( 6057): #47     PipelineOwner.flushLayout (package:flutter/src/rendering/object.dart:887:18)
I/flutter ( 6057): #48     RendererBinding.drawFrame (package:flutter/src/rendering/binding.dart:402:19)
I/flutter ( 6057): #49     WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:884:13)
I/flutter ( 6057): #50     RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:284:5)
I/flutter ( 6057): #51     SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:1113:15)
I/flutter ( 6057): #52     SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:1052:9)
I/flutter ( 6057): #53     SchedulerBinding.scheduleWarmUpFrame.<anonymous closure> (package:flutter/src/scheduler/binding.dart:861:7)
I/flutter ( 6057): (elided 11 frames from class _RawReceivePortImpl, class _Timer, dart:async, and dart:async-patch)
I/flutter ( 6057): 
I/flutter ( 6057): The following RenderObject was being processed when the exception was fired: RenderFlex#7c916 relayoutBoundary=up2 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE:
I/flutter ( 6057):   creator: Column ← Positioned ← Stack ← _BodyBuilder ← MediaQuery ← LayoutId-[<_ScaffoldSlot.body>] ←
I/flutter ( 6057):     CustomMultiChildLayout ← AnimatedBuilder ← DefaultTextStyle ← AnimatedDefaultTextStyle ←
I/flutter ( 6057):     _InkFeatures-[GlobalKey#dd38c ink renderer] ← NotificationListener<LayoutChangedNotification> ← ⋯
I/flutter ( 6057):   parentData: top=200.0; offset=Offset(0.0, 0.0) (can use size)
I/flutter ( 6057):   constraints: BoxConstraints(unconstrained)
I/flutter ( 6057):   size: MISSING
I/flutter ( 6057):   direction: vertical
I/flutter ( 6057):   mainAxisAlignment: start
I/flutter ( 6057):   mainAxisSize: max
I/flutter ( 6057):   crossAxisAlignment: center
I/flutter ( 6057):   verticalDirection: down
I/flutter ( 6057): This RenderObject had the following descendants (showing up to depth 5):
I/flutter ( 6057):     child 1: RenderRepaintBoundary#7ca29 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
I/flutter ( 6057):       child: RenderCustomPaint#abde1 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
I/flutter ( 6057):         child: RenderRepaintBoundary#aee8f NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
I/flutter ( 6057):           child: _RenderScrollSemantics#1ab77 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
I/flutter ( 6057):             child: RenderPointerListener#5c802 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
I/flutter ( 6057): ════════════════════════════════════════════════════════════════════════════════════════════════════
I/flutter ( 6057): Another exception was thrown: RenderBox was not laid out: RenderFlex#7c916 relayoutBoundary=up2 NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
I/flutter ( 6057): Another exception was thrown: NoSuchMethodError: The method '>' was called on null.
I/mple.flutterap( 6057): NativeAlloc concurrent copying GC freed 29925(1495KB) AllocSpace objects, 2(104KB) LOS objects, 30% free, 13MB/19MB, paused 1.018ms total 1.072s
W/System  ( 6057): A resource failed to call release. 
I/flutter ( 6057): Another exception was thrown: NoSuchMethodError: The method '>' was called on null.
D/HostConnection( 6057): HostConnection::get() New Host Connection established 0xb790a9c0, tid 7171
D/HostConnection( 6057): HostComposition ext ANDROID_EMU_CHECKSUM_HELPER_v1 ANDROID_EMU_dma_v1 ANDROID_EMU_direct_mem ANDROID_EMU_host_composition_v1 ANDROID_EMU_host_composition_v2 ANDROID_EMU_YUV420_888_to_NV21 ANDROID_EMU_YUV_Cache ANDROID_EMU_async_unmap_buffer GL_OES_vertex_array_object GL_KHR_texture_compression_astc_ldr ANDROID_EMU_gles_max_version_2 
I/mple.flutterap( 6057): NativeAlloc concurrent copying GC freed 10798(437KB) AllocSpace objects, 0(0B) LOS objects, 30% free, 13MB/19MB, paused 

```

This is the layout :

```
     @override
      Widget build(BuildContext context) {

        return Scaffold(
          body: Stack(
            children: <Widget>[
               GoogleMap(
    //              markers: _markers,
                // polylines:polyline,
                onMapCreated: onMapCreated,
               //  polylines: Set.from(polyline),
               //   myLocationEnabled: true,
                  initialCameraPosition: CameraPosition(
                    target: _pinposition,
                    zoom: 10.0,
                    bearing: 45.0,
                    tilt: 45.0
                  ),
                 markers: Set.from(allMarkers),
                 polylines: _polyLines,
              ),
              Positioned(
                top: 30.0,
                right: 15.0,
                left: 15.0,
                child: Container(
                  height: 50.0,
                  width: double.infinity,
                  decoration: BoxDecoration(
                    borderRadius: BorderRadius.circular(10.0),
                    color: Colors.white
                  ),
                  child: TextField(
                    decoration: InputDecoration(
                      hintText: 'Enter address',
                      border: InputBorder.none,
                      contentPadding: EdgeInsets.only(left: 15.0,top: 15.0),
                      suffixIcon: IconButton(
                        icon: Icon(Icons.search),
                        onPressed: searchandNavigate,
                        iconSize: 30.0,
                      )

                    ),
                    onTap: () async {

                      Prediction p = await PlacesAutocomplete.show(
                          context: context, apiKey: apikey);
                      displayPrediction(p);
                    },
                    onChanged: (val){
                      setState(() {
                        searchAddress = val;

                      });
                    },
                  ),
                ),
              ),
              Positioned(
                top: 200,
                    child: Column(
                      children: <Widget>[
                        Expanded(
                          child: ListView.builder(
                            scrollDirection: Axis.vertical,
                            shrinkWrap: true,
                            //shrinkWrap: true,
                            itemCount: _placesList.length,
                            itemBuilder: (BuildContext context, int index) =>
                                buildPlaceCard(context, index),
                          ),
                        ),
                      ],
                    ),
              )

            ],
          ),

        );
      }

Widget buildPlaceCard(BuildContext context, int index) {

      Container(
        child: Padding(
          padding: const EdgeInsets.only(
            left: 8.0,
            right: 8.0,
          ),
          child: Card(
            child: InkWell(
              child: Row(
                children: <Widget>[
                  Expanded(
                    child: Padding(
                      padding: const EdgeInsets.all(16.0),
                      child: Column(
                        children: <Widget>[
                          Row(
                            children: <Widget>[
                              Text(_placesList[index].name, style: TextStyle(fontSize: 30.0)),
                            ],
                          ),
                          Row(
                            children: <Widget>[
                              Text("Average Budget \$${_placesList[index].averageBudget.toStringAsFixed(2)}"),
                            ],
                          ),
                        ],
                      ),
                    ),
                  ),

                  Column(
                    children: <Widget>[
                      Placeholder(
                        fallbackHeight: 80,
                        fallbackWidth: 80,
                      ),
                    ],
                  )
                ],
              ),
              onTap: () {
                String placename = _placesList[index].name;
                // TODO maybe pass the trip average budget through here too...
                // that would need to be added to the Trip object

              },
            ),
          ),
        ),
      );

  }

```