From b684ffffbef32f614057b2921fdcd79b6e9dce6d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E9=95=BF=E6=9C=88?= <changyue@changyuedeMacBook-Pro.local>
Date: Wed, 17 Jul 2019 15:36:55 +0800
Subject: [PATCH] feat: add CardController

---
 CHANGELOG.md                |  5 ++-
 example/example.dart        |  3 ++
 lib/flutter_tindercard.dart | 70 ++++++++++++++++++++++++++++++++-----
 3 files changed, 68 insertions(+), 10 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8cad681..d9dfb8e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,4 +4,7 @@
 - add `CardDragUpdateCallback` for the swiping position.
 
 ## 0.1.5
-- update `CardSwipeCompleteCallback` with the card's index param:
\ No newline at end of file
+- update `CardSwipeCompleteCallback` with the card's index param:
+
+## 0.1.6
+- add `CardController` to trigger swap from outside.
\ No newline at end of file
diff --git a/example/example.dart b/example/example.dart
index c6480c3..569973c 100644
--- a/example/example.dart
+++ b/example/example.dart
@@ -35,6 +35,8 @@ class _ExampleHomePageState extends State<ExampleHomePage>
 
   @override
   Widget build(BuildContext context) {
+    CardController controller;  //Use this to trigger swap.
+
     return new Scaffold(
       body: new Center(
           child: Container(
@@ -50,6 +52,7 @@ class _ExampleHomePageState extends State<ExampleHomePage>
                   cardBuilder: (context, index) => Card(
                         child: Image.asset('${welcomeImages[index]}'),
                       ),
+                  cardController: controller = CardController(),
                   swipeUpdateCallback: (DragUpdateDetails details) {
                     /// Get swiping card's position
                   },
diff --git a/lib/flutter_tindercard.dart b/lib/flutter_tindercard.dart
index 2781667..d12149d 100644
--- a/lib/flutter_tindercard.dart
+++ b/lib/flutter_tindercard.dart
@@ -13,6 +13,7 @@ class TinderSwapCard extends StatefulWidget {
   int _stackNum;
   CardSwipeCompleteCallback swipeCompleteCallback;
   CardDragUpdateCallback swipeUpdateCallback;
+  CardController cardController;
 
 //  double _maxWidth;
 //  double _minWidth;
@@ -34,6 +35,7 @@ class TinderSwapCard extends StatefulWidget {
       double maxHeight,
       double minWidth,
       double minHeight,
+      this.cardController,
       this.swipeCompleteCallback,
       this.swipeUpdateCallback})
       : this._cardBuilder = cardBuilder,
@@ -84,6 +86,7 @@ class _TinderSwapCardState extends State<TinderSwapCard>
   Alignment frontCardAlign;
   AnimationController _animationController;
   int _currentFront;
+  static int _trigger; // 0: no trigger; -1: trigger left; 1: trigger right
 
   Widget _buildCard(BuildContext context, int realIndex) {
     if (realIndex < 0) {
@@ -94,7 +97,9 @@ class _TinderSwapCardState extends State<TinderSwapCard>
     if (index == widget._stackNum - 1) {
       return Align(
         alignment: _animationController.status == AnimationStatus.forward
-            ? CardAnimation.frontCardAlign(_animationController, frontCardAlign,
+            ? frontCardAlign = CardAnimation.frontCardAlign(
+                    _animationController,
+                    frontCardAlign,
                     _cardAligns[widget._stackNum - 1])
                 .value
             : frontCardAlign,
@@ -156,19 +161,28 @@ class _TinderSwapCardState extends State<TinderSwapCard>
           });
         },
         onPanEnd: (DragEndDetails details) {
-          animateCards();
+          animateCards(0);
         },
       ),
     ));
     return cards;
   }
 
-  animateCards() {
+  animateCards(int trigger) {
+    if (_animationController.isAnimating ||
+        _currentFront + widget._stackNum == 0) {
+      return;
+    }
+    _trigger = trigger;
     _animationController.stop();
     _animationController.value = 0.0;
     _animationController.forward();
   }
 
+  void triggerSwap(int trigger) {
+    animateCards(trigger);
+  }
+
   @override
   void initState() {
     super.initState();
@@ -189,9 +203,11 @@ class _TinderSwapCardState extends State<TinderSwapCard>
           }
         } else {
           if (widget.swipeCompleteCallback != null) {
-            widget.swipeCompleteCallback(frontCardAlign.x < 0
-                ? CardSwipeOrientation.LEFT
-                : CardSwipeOrientation.RIGHT, index);
+            widget.swipeCompleteCallback(
+                frontCardAlign.x < 0
+                    ? CardSwipeOrientation.LEFT
+                    : CardSwipeOrientation.RIGHT,
+                index);
           }
 
           changeCardOrder();
@@ -202,6 +218,8 @@ class _TinderSwapCardState extends State<TinderSwapCard>
 
   @override
   Widget build(BuildContext context) {
+    widget.cardController?.addListener((trigger) => triggerSwap(trigger));
+
     return Stack(children: _buildCards(context));
   }
 
@@ -231,9 +249,17 @@ enum AmassOrientation { TOP, BOTTOM, LEFT, RIGHT }
 class CardAnimation {
   static Animation<Alignment> frontCardAlign(AnimationController controller,
       Alignment beginAlign, Alignment baseAlign) {
-    double endX = beginAlign.x > 0
-        ? (beginAlign.x > 3.0 ? beginAlign.x + 10.0 : baseAlign.x)
-        : (beginAlign.x < -3.0 ? beginAlign.x - 10.0 : baseAlign.x);
+    double endX;
+
+    if (_TinderSwapCardState._trigger == 0) {
+      endX = beginAlign.x > 0
+          ? (beginAlign.x > 3.0 ? beginAlign.x + 10.0 : baseAlign.x)
+          : (beginAlign.x < -3.0 ? beginAlign.x - 10.0 : baseAlign.x);
+    } else if (_TinderSwapCardState._trigger == -1) {
+      endX = beginAlign.x - 5.0;
+    } else {
+      endX = beginAlign.x + 5.0;
+    }
     return new AlignmentTween(
             begin: beginAlign, end: new Alignment(endX, baseAlign.y))
         .animate(
@@ -258,3 +284,29 @@ class CardAnimation {
         new CurvedAnimation(parent: controller, curve: Curves.easeOut));
   }
 }
+
+typedef TriggerListener = void Function(int trigger);
+
+class CardController {
+  TriggerListener _listener;
+
+  void triggerLeft() {
+    if (_listener != null) {
+      _listener(-1);
+    }
+  }
+
+  void triggerRight() {
+    if (_listener != null) {
+      _listener(1);
+    }
+  }
+
+  void addListener(listener) {
+    _listener = listener;
+  }
+
+  void removeListener() {
+    _listener = null;
+  }
+}