Merge pull request #39 from deepikahr/GFBottomsheet

Gf bottomsheet completed

Author: deepikahr

lib/components/bottom_sheet/gf_bottom_sheet.dart

@@ -1,21 +1,25 @@
+import 'dart:async';
 import 'package:flutter/material.dart';
 
 class GFBottomSheet extends StatefulWidget {
   GFBottomSheet({
     Key key,
-    @required this.stickyHeader,
     @required this.contentBody,
+    this.stickyHeader,
     this.stickyFooter,
     this.controller,
     this.minContentHeight = 0,
     this.maxContentHeight = 300,
     this.elevation = 0.0,
-    this.stickyFooterHeight,
+    this.stickyFooterHeight = 0.0,
+    this.stickyHeaderHeight = 0.0,
+    this.animationDuration = 300,
+    this.enableExpandableContent = false,
   })  : assert(elevation >= 0.0),
         assert(minContentHeight >= 0.0),
         super(key: key) {
     controller.height = minContentHeight;
-    controller.smoothness = 500;
+    controller.animationDuration = animationDuration;
   }
 
   /// [minContentHeight] controls the minimum height of the content body.
@@ -31,35 +35,49 @@ class GFBottomSheet extends StatefulWidget {
   final Widget stickyHeader;
 
   /// [contentBody] is the body of GFBottomSheet.
-  /// User can interact by tapping the [contentBody]
+  /// User can interact by swiping or tapping the [contentBody]
   final Widget contentBody;
 
   /// [stickyFooter] is the footer of GFBottomSheet.
   /// User can interact by swiping or tapping the [stickyFooter]
   final Widget stickyFooter;
 
-  /// [stickyFooterHeight] defines the height of GFBottokSheet footer.
+  /// [stickyFooterHeight] defines the height of GFBottomSheet's [stickyFooter].
   final double stickyFooterHeight;
 
+  /// [stickyHeaderHeight] defines the height of GFBottomSheet's [stickyHeader].
+  final double stickyHeaderHeight;
+
   /// [elevation] controls shadow below the GFBottomSheet material.
-  /// Must be greater or equalto 0. Default value is 0.
+  /// Must be greater or equal to 0. Default value is 0.
   final double elevation;
 
+  ///[enableExpandableContent] allows [contentBody] to expand.
+  /// Default value is false.
+  final bool enableExpandableContent;
+
   /// [controller] used to control GFBottomSheet behavior like hide/show
   final GFBottomSheetController controller;
 
+  /// Defines the drag animation duration of the GFBottomSheet
+  /// Default value is 300.
+  final int animationDuration;
+
   @override
   _GFBottomSheetState createState() => _GFBottomSheetState();
 }
 
 class _GFBottomSheetState extends State<GFBottomSheet>
     with TickerProviderStateMixin {
+  final StreamController<double> controller = StreamController.broadcast();
   bool isDragDirectionUp;
   bool showBottomSheet = false;
   Function _controllerListener;
+  double position;
+  bool showContent = false;
 
   void _onVerticalDragUpdate(data) {
-    _setSmoothness();
+    _setAnimationDuration();
     if (((widget.controller.height - data.delta.dy) >
             widget.minContentHeight) &&
         ((widget.controller.height - data.delta.dy) <
@@ -70,7 +88,7 @@ class _GFBottomSheetState extends State<GFBottomSheet>
   }
 
   void _onVerticalDragEnd(data) {
-    _setSmoothness();
+    _setAnimationDuration();
     if (isDragDirectionUp && widget.controller.value) {
       _showBottomSheet();
     } else if (!isDragDirectionUp && !widget.controller.value) {
@@ -89,7 +107,7 @@ class _GFBottomSheetState extends State<GFBottomSheet>
   @override
   void initState() {
     super.initState();
-
+    position = widget.minContentHeight;
     widget.controller.value = showBottomSheet;
     _controllerListener = () {
       widget.controller.value ? _showBottomSheet() : _hideBottomSheet();
@@ -113,28 +131,62 @@ class _GFBottomSheetState extends State<GFBottomSheet>
                 onVerticalDragUpdate: _onVerticalDragUpdate,
                 onVerticalDragEnd: _onVerticalDragEnd,
                 onTap: _onTap,
-                child: widget.stickyHeader,
+                child: Container(
+                  height: widget.stickyHeaderHeight,
+                  child: widget.stickyHeader,
+                ),
               ),
-        AnimatedBuilder(
-          animation: widget.controller,
-          builder: (_, Widget child) => AnimatedContainer(
-            curve: Curves.easeOut,
-            duration: Duration(milliseconds: widget.controller.smoothness),
-            height: widget.controller.height,
-            child: GestureDetector(
-                onVerticalDragUpdate: _onVerticalDragUpdate,
-                onVerticalDragEnd: _onVerticalDragEnd,
-                onTap: _onTap,
-                child: widget.contentBody),
-          ),
-        ),
-        widget.stickyFooter != null
+        !widget.enableExpandableContent
             ? AnimatedBuilder(
                 animation: widget.controller,
                 builder: (_, Widget child) => AnimatedContainer(
                   curve: Curves.easeOut,
-                  duration:
-                      Duration(milliseconds: widget.controller.smoothness),
+                  duration: Duration(
+                      milliseconds: widget.controller.animationDuration),
+                  height: widget.controller.height,
+                  child: GestureDetector(
+                      onVerticalDragUpdate: _onVerticalDragUpdate,
+                      onVerticalDragEnd: _onVerticalDragEnd,
+                      onTap: _onTap,
+                      child: widget.contentBody),
+                ),
+              )
+            : showContent
+                ? StreamBuilder(
+                    stream: controller.stream,
+                    initialData: widget.controller.height,
+                    builder: (context, snapshot) => GestureDetector(
+                        onVerticalDragUpdate: (DragUpdateDetails details) {
+                          if (((widget.controller.height - details.delta.dy) >
+                                  widget.minContentHeight) &&
+                              ((widget.controller.height - details.delta.dy) <
+                                  (MediaQuery.of(context).size.height * 0.8 -
+                                      widget.stickyFooterHeight -
+                                      widget.stickyHeaderHeight))) {
+                            isDragDirectionUp = details.delta.dy <= 0;
+                            widget.controller.height -= details.delta.dy;
+                          }
+                          controller.add(widget.controller.height);
+                        },
+                        onVerticalDragEnd: _onVerticalDragEnd,
+                        onTap: _onTap,
+                        behavior: HitTestBehavior.translucent,
+                        child: Container(
+                          height: snapshot.hasData == null
+                              ? widget.minContentHeight
+                              : snapshot.data,
+                          child: widget.contentBody,
+                        )),
+                  )
+                : Container(),
+        widget.stickyFooter == null
+            ? Container()
+            : AnimatedBuilder(
+                animation: widget.controller,
+                builder: (_, Widget child) => AnimatedContainer(
+                  curve: Curves.easeOut,
+                  duration: Duration(
+                      milliseconds: widget.controller.animationDuration),
                   height: widget.controller.height != widget.minContentHeight
                       ? widget.stickyFooterHeight
                       : 0.0,
@@ -145,8 +197,7 @@ class _GFBottomSheetState extends State<GFBottomSheet>
                     child: widget.stickyFooter,
                   ),
                 ),
-              )
-            : Container(),
+              ),
       ],
     );
     return Material(
@@ -156,10 +207,16 @@ class _GFBottomSheetState extends State<GFBottomSheet>
   }
 
   void _hideBottomSheet() {
+    setState(() {
+      showContent = false;
+    });
     widget.controller.height = widget.minContentHeight;
   }
 
   void _showBottomSheet() {
+    setState(() {
+      showContent = true;
+    });
     widget.controller.height = widget.maxContentHeight;
   }
 
@@ -169,8 +226,8 @@ class _GFBottomSheetState extends State<GFBottomSheet>
     super.dispose();
   }
 
-  void _setSmoothness() {
-    widget.controller.smoothness = 500;
+  void _setAnimationDuration() {
+    widget.controller.animationDuration = widget.animationDuration;
   }
 }
 
@@ -180,8 +237,8 @@ class GFBottomSheetController extends ValueNotifier<bool> {
   /// Defines the height of the GFBottomSheet's contentBody
   double _height;
 
-  /// Defines the drag animation smoothness of the GFBottomSheet
-  int smoothness;
+  /// Defines the drag animation duration of the GFBottomSheet
+  int animationDuration;
 
   // ignore: unnecessary_getters_setters
   set height(double value) => _height = value;