Add scrollable frames

UnsignedArduino · UnsignedArduino · commit 9ff879b3e893 · 2021-05-23T11:52:37.000-04:00
diff --git a/Examples/Widgets/ScrollableFrame/ScrollableFrame.py b/Examples/Widgets/ScrollableFrame/ScrollableFrame.py
@@ -0,0 +1,22 @@
+from TkZero.Button import Button
+from TkZero.Frame import ScrollableFrame
+from TkZero.MainWindow import MainWindow
+
+# Create the main window and set a title
+root = MainWindow()
+root.title = "Scrollable Frame Example"
+
+# Create a scrollable frame
+scrollable_frame = ScrollableFrame(root, x_scrolling=True, y_scrolling=True)
+scrollable_frame.grid(row=0, column=0)
+
+# Create a bunch of buttons in the scrollable frame
+for x in range(10):
+    for y in range(20):
+        # Note the usage of the frame attribute of the scrollable frame instead
+        # of using it directly.
+        b = Button(scrollable_frame.frame, text=f"{x}, {y}")
+        b.grid(row=y, column=x)
+
+# Start the mainloop like in Tkinter
+root.mainloop()
diff --git a/Tests/test_Frame.py b/Tests/test_Frame.py
@@ -5,7 +5,7 @@
 import unittest
 
 from TkZero import Style
-from TkZero.Frame import Frame
+from TkZero.Frame import Frame, ScrollableFrame
 from TkZero.Label import Label
 from TkZeroUnitTest import TkTestCase
 
@@ -14,6 +14,7 @@ class FrameTest(TkTestCase):
     def test_no_params(self):
         with self.assertRaises(TypeError):
             Frame()
+
     def test_bad_params(self):
         with self.assertRaises(TypeError):
             Frame(parent=1)
@@ -63,5 +64,60 @@ def test_style(self):
             f.apply_style(123456789)
 
 
+class ScrollableFrameTest(TkTestCase):
+    def test_no_params(self):
+        with self.assertRaises(TypeError):
+            ScrollableFrame()
+
+    def test_bad_params(self):
+        with self.assertRaises(TypeError):
+            ScrollableFrame(parent=1)
+
+    def test_good_params(self):
+        ScrollableFrame(self.root, x_scrolling=True,
+                        y_scrolling=True).grid(row=0, column=0)
+
+    def test_width_height(self):
+        f = ScrollableFrame(self.root)
+        f.grid(row=0, column=0)
+        f.width = 500
+        f.height = 200
+        self.root.update()
+        self.assertEqual(f.width, 500)
+        self.assertEqual(f.height, 200)
+        with self.assertRaises(TypeError):
+            f.width = "la"
+        with self.assertRaises(ValueError):
+            f.width = 0
+        with self.assertRaises(TypeError):
+            f.height = "lo"
+        with self.assertRaises(ValueError):
+            f.height = -1
+
+    def test_enabled(self):
+        f = ScrollableFrame(self.root)
+        f.grid(row=0, column=0)
+        self.assertTrue(f.enabled)
+        Label(f.frame).grid(row=0, column=0)
+        Label(f.frame).grid(row=1, column=0)
+        Frame(f.frame).grid(row=2, column=0)
+        self.root.update()
+        f.enabled = False
+        self.assertFalse(f.enabled)
+        with self.assertRaises(TypeError):
+            f.enabled = []
+
+    def test_style(self):
+        f = ScrollableFrame(self.root)
+        f.grid(row=0, column=0)
+        Style.define_style(Style.WidgetStyleRoots.Frame, "Test",
+                           background="red")
+        f.apply_style("Test")
+        self.assertEqual(f.frame.cget("style"), "Test.TFrame")
+        self.root.update()
+        with self.assertRaises(TypeError):
+            f.apply_style(123456789)
+
+
 if __name__ == '__main__':
     unittest.main()
diff --git a/TkZero/Frame.py b/TkZero/Frame.py
@@ -6,6 +6,8 @@
 from tkinter import ttk
 from typing import Union
 
+from TkZero import Platform
+
 
 class Frame(ttk.Frame):
     def __init__(self, parent: Union[tk.Widget, Union[tk.Tk, tk.Toplevel]]):
@@ -145,3 +147,142 @@ def apply_style(self, style_name: str) -> None:
                 f"(type passed in: {repr(type(style_name))})"
             )
         self.configure(style=f"{style_name}.{self._style_root}")
+
+
+class ScrollableFrame(Frame):
+    def __init__(
+        self,
+        parent: Union[tk.Widget, Union[tk.Tk, tk.Toplevel]],
+        x_scrolling: bool = False,
+        y_scrolling: bool = True,
+    ):
+        """
+        Create a scrollable frame.
+        MAKE SURE WHEN GRIDING WIDGETS TO THIS FRAME TO USE THE FRAME
+        ATTRIBUTE INSTEAD OF THIS FRAME DIRECTLY.
+
+        :param parent: The parent of this frame.
+        :param x_scrolling: A bool on whether to add a scrollbar in the x
+         direction.
+        :param y_scrolling: A bool on whether to add a scrollbar in the y
+         direction.
+        """
+        # https://blog.teclado.com/tkinter-scrollable-frames/
+        super().__init__(parent)
+        self.canvas = tk.Canvas(self)
+        if x_scrolling:
+            x_scrollbar = ttk.Scrollbar(
+                self, orient=tk.HORIZONTAL, command=self.canvas.xview
+            )
+        if y_scrolling:
+            y_scrollbar = ttk.Scrollbar(
+                self, orient=tk.VERTICAL, command=self.canvas.yview
+            )
+        self.frame = Frame(self.canvas)
+        self.frame.bind(
+            "<Configure>",
+            lambda _: self.canvas.configure(scrollregion=self.canvas.bbox(tk.ALL)),
+        )
+        self.canvas.create_window((0, 0), window=self.frame, anchor=tk.NW)
+        if x_scrolling:
+            self.canvas.configure(xscrollcommand=x_scrollbar.set)
+        if y_scrolling:
+            self.canvas.configure(yscrollcommand=y_scrollbar.set)
+        self.canvas.grid(row=0, column=0)
+        if x_scrolling:
+            x_scrollbar.grid(row=1, column=0, sticky=tk.NSEW)
+        if y_scrolling:
+            y_scrollbar.grid(row=0, column=1, sticky=tk.NSEW)
+        # https://stackoverflow.com/a/37858368/10291933
+        self.frame.bind("<Enter>", self._bind_to_mousewheel)
+        self.frame.bind("<Leave>", self._unbind_to_mousewheel)
+        self._shift_pressed = False
+        # https://stackoverflow.com/a/8089241/10291933
+        # http://www.tcl.tk/man/tcl8.4/TkCmd/keysyms.htm
+        self.frame.bind_all("<Shift_L>", lambda _: self._set_shift_pressed(True))
+        self.frame.bind_all("<Shift_R>", lambda _: self._set_shift_pressed(True))
+        self.frame.bind_all(
+            "<KeyRelease-Shift_L>", lambda _: self._set_shift_pressed(False)
+        )
+        self.frame.bind_all(
+            "<KeyRelease-Shift_R>", lambda _: self._set_shift_pressed(False)
+        )
+
+    def _set_shift_pressed(self, is_pressed: bool) -> None:
+        """
+        Set whether shift is pressed or not.
+
+        :param is_pressed: A bool.
+        :return: None.
+        """
+        self._shift_pressed = is_pressed
+
+    def _bind_to_mousewheel(self, event) -> None:
+        """
+        Bind to the mousewheel.
+
+        :param event: An event that Tkinter passes in.
+        :return: None
+        """
+        self.canvas.bind_all("<MouseWheel>", self._on_mousewheel)
+
+    def _unbind_to_mousewheel(self, event) -> None:
+        """
+        Unbind to the mousewheel.
+
+        :param event: An event that Tkinter passes in.
+        :return: None
+        """
+        self.canvas.unbind_all("<MouseWheel>")
+
+    def _on_mousewheel(self, event) -> None:
+        """
+        A callback for the mousewheel to scroll.
+
+        :param event: An event that Tkinter passes in.
+        :return: None.
+        """
+        if Platform.on_aqua(self):
+            scroll = str(int(-1 * event.delta))
+        else:
+            scroll = str(int(-1 * (event.delta / 120)))
+        if self._shift_pressed:
+            self.canvas.xview_scroll(scroll, tk.UNITS)
+        else:
+            self.canvas.yview_scroll(scroll, tk.UNITS)
+
+    def _enable_children(
+        self, parent: Union[tk.Widget, None] = None, enable: bool = True
+    ) -> None:
+        """
+        Enable or disable the children.
+
+        :param parent: A tk.Widget that is our parent. If None then default to
+         self.
+        :param enable: Whether to enable or disable the children.
+        :return: None.
+        """
+        if parent is None:
+            parent = self.frame
+        for child in parent.winfo_children():
+            if child.winfo_class() not in ("Frame", "LabelFrame"):
+                try:
+                    child.state(["!disabled" if enable else "disabled"])
+                except AttributeError:
+                    child.configure(state=tk.NORMAL if enable else tk.DISABLED)
+            else:
+                self._enable_children(parent, enable)
+
+    def apply_style(self, style_name: str) -> None:
+        """
+        Apply a theme to this frame.
+
+        :param style_name: The name of the theme as a str, ex. "Warning"
+        :return: None.
+        """
+        if not isinstance(style_name, str):
+            raise TypeError(
+                f"style_name is not a str! "
+                f"(type passed in: {repr(type(style_name))})"
+            )
+        self.frame.configure(style=f"{style_name}.{self._style_root}")
diff --git a/docs/Frame.html b/docs/Frame.html
