添加流式布局

README.md

@@ -124,6 +124,19 @@ A collection of commonly used widgets.
         <img src="screenshot/state_tooltip.gif" />
       </td>
     </tr>
+    <tr>
+      <td>
+        Flow Layout
+      </td>
+      <td>
+        <code>FlowLayout</code>
+      </td>
+    </tr>
+    <tr>
+      <td colspan="2" align="center">
+        <img src="screenshot/flow_layout.gif" />
+      </td>
+    </tr>
     <tr>
       <td>
         Smooth Scroll Area

widgets/flow_layout/demo.py

+# coding:utf-8
+import sys
+from PyQt5.QtWidgets import QApplication, QWidget, QPushButton
+
+from flow_layout import FlowLayout
+
+
+class Demo(QWidget):
+
+    def __init__(self):
+        super().__init__()
+        layout = FlowLayout(self)
+
+        layout.setContentsMargins(30, 30, 30, 30)
+        layout.setVerticalSpacing(20)
+        layout.setHorizontalSpacing(10)
+
+        layout.addWidget(QPushButton('aiko'))
+        layout.addWidget(QPushButton('刘静爱'))
+        layout.addWidget(QPushButton('柳井爱子'))
+        layout.addWidget(QPushButton('aiko 赛高'))
+        layout.addWidget(QPushButton('aiko 太爱啦😘'))
+
+        self.resize(250, 300)
+        self.setStyleSheet('Demo{background: white} QPushButton{padding: 5px 10px; font:15px "Microsoft YaHei"}')
+
+
+if __name__ == '__main__':
+    app = QApplication(sys.argv)
+    w = Demo()
+    w.show()
+    app.exec_()

widgets/flow_layout/flow_layout.py

+# coding:utf-8
+from PyQt5.QtCore import QSize, QPoint, Qt, QMargins, QRect
+from PyQt5.QtWidgets import QLayout
+
+
+class FlowLayout(QLayout):
+    def __init__(self, parent=None):
+        super().__init__(parent)
+        self.__items = []
+        self.__verticalSpacing = 10
+        self.__horizontalSpacing = 10
+        self.__margins = QMargins(0, 0, 0, 0)
+        super().setContentsMargins(self.__margins)
+
+    def addItem(self, item):
+        self.__items.append(item)
+
+    def count(self):
+        return len(self.__items)
+
+    def itemAt(self, index: int):
+        if 0 <= index < len(self.__items):
+            return self.__items[index]
+
+        return None
+
+    def takeAt(self, index: int):
+        if 0 <= index < len(self.__items):
+            return self.__items.pop(index)
+
+        return None
+
+    def removeAllWidgets(self):
+        """ 从布局中移除所有的部件 """
+        while self.__items:
+            self.takeAt(0)
+
+    def expandingDirections(self):
+        return Qt.Orientation(0)
+
+    def hasHeightForWidth(self):
+        return True
+
+    def heightForWidth(self, width: int):
+        """ 根据宽度计算最小高度 """
+        return self.__do_layout(QRect(0, 0, width, 0), False)
+
+    def setGeometry(self, rect: QRect):
+        super().setGeometry(rect)
+        self.__do_layout(rect, True)
+
+    def sizeHint(self):
+        return self.minimumSize()
+
+    def minimumSize(self):
+        size = QSize()
+
+        for item in self.__items:
+            size = size.expandedTo(item.minimumSize())
+
+        m = self.__margins
+        size += QSize(m.left()+m.right(), m.top()+m.bottom())
+
+        return size
+
+    def setVerticalSpacing(self, spacing: int):
+        """ 设置竖直方向的间距 """
+        self.__verticalSpacing = spacing
+
+    def verticalSpacing(self):
+        """ 返回竖直方向的间距 """
+        return self.__verticalSpacing
+
+    def setHorizontalSpacing(self, spacing: int):
+        """ 设置水平方向的间距 """
+        self.__horizontalSpacing = spacing
+
+    def horizontalSpacing(self):
+        """ 返回水平方向间距 """
+        return self.__horizontalSpacing
+
+    def __do_layout(self, rect: QRect, move: bool):
+        """ 根据大小调整小部件位置 """
+        margin = self.contentsMargins()
+        x = rect.x() + margin.left()
+        y = rect.y() + margin.top()
+        rowHeight = 0
+        spaceX = self.horizontalSpacing()
+        spaceY = self.verticalSpacing()
+
+        for item in self.__items:
+            nextX = x + item.sizeHint().width() + spaceX
+
+            if nextX - spaceX > rect.right() and rowHeight > 0:
+                x = rect.x() + margin.left()
+                y = y + rowHeight + spaceY
+                nextX = x + item.sizeHint().width() + spaceX
+                rowHeight = 0
+
+            if move:
+                item.setGeometry(QRect(QPoint(x, y), item.sizeHint()))
+
+            x = nextX
+            rowHeight = max(rowHeight, item.sizeHint().height())
+
+        return y + rowHeight - rect.y()