new tree control

examples/json_tree.py

@@ -0,0 +1,79 @@
+import json
+
+from rich.text import Text
+
+from textual.app import App, ComposeResult
+from textual.widgets import Header, Footer, Tree, TreeNode
+
+
+class TreeApp(App):
+
+    BINDINGS = [
+        ("a", "add", "Add node"),
+        ("c", "clear", "Clear"),
+        ("t", "toggle_root", "Toggle root"),
+    ]
+
+    def compose(self) -> ComposeResult:
+        yield Header()
+        yield Footer()
+        yield Tree("Root")
+
+    @classmethod
+    def add_json(cls, node: TreeNode, json_data: object) -> None:
+        """Adds JSON data to a node.
+
+        Args:
+            node (TreeNode): A Tree node.
+            json_data (object): An object decoded from JSON.
+        """
+
+        from rich.highlighter import ReprHighlighter
+
+        highlighter = ReprHighlighter()
+
+        def add_node(name: str, node: TreeNode, data: object) -> None:
+            if isinstance(data, dict):
+                node._label = Text(f"{{}} {name}")
+                for key, value in data.items():
+                    new_node = node.add("")
+                    add_node(key, new_node, value)
+            elif isinstance(data, list):
+                node._label = Text(f"[] {name}")
+                for index, value in enumerate(data):
+                    new_node = node.add("")
+                    add_node(str(index), new_node, value)
+            else:
+                node._allow_expand = False
+                if name:
+                    label = Text.assemble(
+                        Text.from_markup(f"[b]{name}[/b]="), highlighter(repr(data))
+                    )
+                else:
+                    label = Text(repr(data))
+                node._label = label
+
+        add_node("JSON", node, json_data)
+
+    def on_mount(self) -> None:
+        with open("food.json") as data_file:
+            self.json_data = json.load(data_file)
+
+    def action_add(self) -> None:
+        tree = self.query_one(Tree)
+        json_node = tree.root.add("JSON")
+        self.add_json(json_node, self.json_data)
+        tree.root.expand()
+
+    def action_clear(self) -> None:
+        tree = self.query_one(Tree)
+        tree.clear()
+
+    def action_toggle_root(self) -> None:
+        tree = self.query_one(Tree)
+        tree.show_root = not tree.show_root
+
+
+if __name__ == "__main__":
+    app = TreeApp()
+    app.run()