Expanding fr (#2221)

* forced fr to expand

* margin size

* remove comment

* missing snapshot

* snapshot tests

* changelog

* optimize

* snapshot fix

* snapshot update

* snapshot and fixes

* docstrings [skip ci]

tests/snapshot_tests/snapshot_apps/auto_fr.py

@@ -0,0 +1,40 @@
+from textual.app import App, ComposeResult
+from textual.widget import Widget
+from textual.widgets import Label
+
+
+class FRApp(App):
+    CSS = """    
+    Screen {
+        align: center middle;
+        border: solid cyan;
+    }
+
+    #container {  
+        width: 30;      
+        height: auto;
+        border: solid green;
+        overflow-y: auto;
+    }
+
+    #child {
+        height: 1fr;
+        border: solid red;       
+    }
+
+    #bottom {
+        margin: 1 2;    
+        background: $primary;
+    }
+    """
+
+    def compose(self) -> ComposeResult:
+        with Widget(id="container"):
+            yield Label("Hello one line", id="top")
+            yield Widget(id="child")
+            yield Label("Two\nLines with 1x2 margin", id="bottom")
+
+
+if __name__ == "__main__":
+    app = FRApp()
+    app.run()

tests/snapshot_tests/snapshot_apps/fr_margins.py

@@ -0,0 +1,35 @@
+from textual.app import App, ComposeResult
+from textual.widgets import Label
+from textual.containers import Container
+
+
+# Test fr dimensions and margins work in an auto container
+# https://github.com/Textualize/textual/issues/2220
+class TestApp(App):
+    CSS = """
+    Container {
+        background: green 20%;
+        border: heavy green;
+        width: auto;
+        height: auto;
+        overflow: hidden;
+    }
+
+    Label {
+        background: green 20%;      
+        width: 1fr;
+        height: 1fr;
+        margin: 2 2;            
+    }
+    """
+
+    def compose(self) -> ComposeResult:
+        with Container():
+            yield Label("Hello")
+            yield Label("World")
+            yield Label("!!")
+
+
+if __name__ == "__main__":
+    app = TestApp()
+    app.run()

tests/snapshot_tests/test_snapshots.py

@@ -388,6 +388,16 @@ def test_dock_scroll(snap_compare):
     assert snap_compare(SNAPSHOT_APPS_DIR / "dock_scroll.py", terminal_size=(80, 25))
 
 
+def test_auto_fr(snap_compare):
+    # https://github.com/Textualize/textual/issues/2220
+    assert snap_compare(SNAPSHOT_APPS_DIR / "auto_fr.py", terminal_size=(80, 25))
+
+
+def test_fr_margins(snap_compare):
+    # https://github.com/Textualize/textual/issues/2220
+    assert snap_compare(SNAPSHOT_APPS_DIR / "fr_margins.py", terminal_size=(80, 25))
+
+
 def test_scroll_visible(snap_compare):
     # https://github.com/Textualize/textual/issues/2181
     assert snap_compare(SNAPSHOT_APPS_DIR / "scroll_visible.py", press=["t"])

tests/test_box_model.py

@@ -2,206 +2,190 @@ from __future__ import annotations
 
 from fractions import Fraction
 
-from textual.box_model import BoxModel, get_box_model
+from textual.box_model import BoxModel
 from textual.css.styles import Styles
 from textual.geometry import Size, Spacing
+from textual.widget import Widget
 
 
 def test_content_box():
-    styles = Styles()
-    styles.width = 10
-    styles.height = 8
-    styles.padding = 1
-    styles.border = ("solid", "red")
-
     one = Fraction(1)
 
+    class TestWidget(Widget):
+        def get_content_width(self, container: Size, parent: Size) -> int:
+            assert False, "must not be called"
+
+        def get_content_height(self, container: Size, parent: Size) -> int:
+            assert False, "must not be called"
+
+    widget = TestWidget()
+
     # border-box is default
-    assert styles.box_sizing == "border-box"
+    assert widget.styles.box_sizing == "border-box"
 
-    def get_auto_width(container: Size, parent: Size) -> int:
-        assert False, "must not be called"
+    widget.styles.width = 10
+    widget.styles.height = 8
+    widget.styles.padding = 1
+    widget.styles.border = ("solid", "red")
 
-    def get_auto_height(container: Size, parent: Size) -> int:
-        assert False, "must not be called"
-
-    box_model = get_box_model(
-        styles, Size(60, 20), Size(80, 24), one, one, get_auto_width, get_auto_height
+    box_model = widget._get_box_model(
+        Size(60, 20),
+        Size(80, 24),
+        one,
+        one,
     )
     # Size should be inclusive of padding / border
     assert box_model == BoxModel(Fraction(10), Fraction(8), Spacing(0, 0, 0, 0))
 
     # Switch to content-box
-    styles.box_sizing = "content-box"
+    widget.styles.box_sizing = "content-box"
 
-    box_model = get_box_model(
-        styles, Size(60, 20), Size(80, 24), one, one, get_auto_width, get_auto_height
-    )
+    box_model = widget._get_box_model(Size(60, 20), Size(80, 24), one, one)
     # width and height have added padding / border to accommodate content
     assert box_model == BoxModel(Fraction(14), Fraction(12), Spacing(0, 0, 0, 0))
 
 
 def test_width():
     """Test width settings."""
-    styles = Styles()
+
     one = Fraction(1)
 
-    def get_auto_width(container: Size, parent: Size) -> int:
-        return 10
+    class TestWidget(Widget):
+        def get_content_width(self, container: Size, parent: Size) -> int:
+            return 10
 
-    def get_auto_height(container: Size, parent: Size, width: int) -> int:
-        return 10
+        def get_content_height(self, container: Size, parent: Size, width: int) -> int:
+            return 10
 
-    box_model = get_box_model(
-        styles, Size(60, 20), Size(80, 24), one, one, get_auto_width, get_auto_height
-    )
+    widget = TestWidget()
+    styles = widget.styles
+    box_model = widget._get_box_model(Size(60, 20), Size(80, 24), one, one)
     assert box_model == BoxModel(Fraction(60), Fraction(20), Spacing(0, 0, 0, 0))
 
     # Add a margin and check that it is reported
     styles.margin = (1, 2, 3, 4)
 
-    box_model = get_box_model(
-        styles, Size(60, 20), Size(80, 24), one, one, get_auto_width, get_auto_height
-    )
+    box_model = widget._get_box_model(Size(60, 20), Size(80, 24), one, one)
     assert box_model == BoxModel(Fraction(54), Fraction(16), Spacing(1, 2, 3, 4))
 
     # Set width to auto-detect
     styles.width = "auto"
 
-    box_model = get_box_model(
-        styles, Size(60, 20), Size(80, 24), one, one, get_auto_width, get_auto_height
-    )
+    box_model = widget._get_box_model(Size(60, 20), Size(80, 24), one, one)
     # Setting width to auto should call get_auto_width
     assert box_model == BoxModel(Fraction(10), Fraction(16), Spacing(1, 2, 3, 4))
 
     # Set width to 100 vw which should make it the width of the parent
     styles.width = "100vw"
 
-    box_model = get_box_model(
-        styles, Size(60, 20), Size(80, 24), one, one, get_auto_width, get_auto_height
-    )
+    box_model = widget._get_box_model(Size(60, 20), Size(80, 24), one, one)
     assert box_model == BoxModel(Fraction(80), Fraction(16), Spacing(1, 2, 3, 4))
 
     # Set the width to 100% should make it fill the container size
     styles.width = "100%"
 
-    box_model = get_box_model(
-        styles, Size(60, 20), Size(80, 24), one, one, get_auto_width, get_auto_height
-    )
+    box_model = widget._get_box_model(Size(60, 20), Size(80, 24), one, one)
     assert box_model == BoxModel(Fraction(54), Fraction(16), Spacing(1, 2, 3, 4))
 
     styles.width = "100vw"
     styles.max_width = "50%"
 
-    box_model = get_box_model(
-        styles, Size(60, 20), Size(80, 24), one, one, get_auto_width, get_auto_height
-    )
+    box_model = widget._get_box_model(Size(60, 20), Size(80, 24), one, one)
     assert box_model == BoxModel(Fraction(30), Fraction(16), Spacing(1, 2, 3, 4))
 
 
 def test_height():
     """Test height settings."""
-    styles = Styles()
+
     one = Fraction(1)
 
-    def get_auto_width(container: Size, parent: Size) -> int:
-        return 10
+    class TestWidget(Widget):
+        def get_content_width(self, container: Size, parent: Size) -> int:
+            return 10
 
-    def get_auto_height(container: Size, parent: Size, width: int) -> int:
-        return 10
+        def get_content_height(self, container: Size, parent: Size, width: int) -> int:
+            return 10
 
-    box_model = get_box_model(
-        styles, Size(60, 20), Size(80, 24), one, one, get_auto_width, get_auto_height
-    )
+    widget = TestWidget()
+    styles = widget.styles
+
+    box_model = widget._get_box_model(Size(60, 20), Size(80, 24), one, one)
     assert box_model == BoxModel(Fraction(60), Fraction(20), Spacing(0, 0, 0, 0))
 
     # Add a margin and check that it is reported
     styles.margin = (1, 2, 3, 4)
 
-    box_model = get_box_model(
-        styles, Size(60, 20), Size(80, 24), one, one, get_auto_width, get_auto_height
-    )
+    box_model = widget._get_box_model(Size(60, 20), Size(80, 24), one, one)
     assert box_model == BoxModel(Fraction(54), Fraction(16), Spacing(1, 2, 3, 4))
 
     # Set height to 100 vw which should make it the height of the parent
     styles.height = "100vh"
 
-    box_model = get_box_model(
-        styles, Size(60, 20), Size(80, 24), one, one, get_auto_width, get_auto_height
-    )
+    box_model = widget._get_box_model(Size(60, 20), Size(80, 24), one, one)
     assert box_model == BoxModel(Fraction(54), Fraction(24), Spacing(1, 2, 3, 4))
 
     # Set the height to 100% should make it fill the container size
     styles.height = "100%"
 
-    box_model = get_box_model(
-        styles, Size(60, 20), Size(80, 24), one, one, get_auto_width, get_auto_height
-    )
+    box_model = widget._get_box_model(Size(60, 20), Size(80, 24), one, one)
     assert box_model == BoxModel(Fraction(54), Fraction(16), Spacing(1, 2, 3, 4))
 
     styles.height = "auto"
     styles.margin = 2
 
-    box_model = get_box_model(
-        styles, Size(60, 20), Size(80, 24), one, one, get_auto_width, get_auto_height
-    )
+    box_model = widget._get_box_model(Size(60, 20), Size(80, 24), one, one)
+    print(box_model)
     assert box_model == BoxModel(Fraction(56), Fraction(10), Spacing(2, 2, 2, 2))
 
     styles.margin = 1, 2, 3, 4
     styles.height = "100vh"
     styles.max_height = "50%"
 
-    box_model = get_box_model(
-        styles, Size(60, 20), Size(80, 24), one, one, get_auto_width, get_auto_height
-    )
+    box_model = widget._get_box_model(Size(60, 20), Size(80, 24), one, one)
     assert box_model == BoxModel(Fraction(54), Fraction(10), Spacing(1, 2, 3, 4))
 
-    # Set height to auto and set content height to 0 to check if box collapses.
-    styles.height = "auto"
-
-    box_model = get_box_model(
-        styles, Size(60, 20), Size(80, 24), one, one, get_auto_width, lambda *_: 0
-    )
-    assert box_model == BoxModel(Fraction(54), Fraction(0), Spacing(1, 2, 3, 4))
-
 
 def test_max():
     """Check that max_width and max_height are respected."""
-    styles = Styles()
+    one = Fraction(1)
+
+    class TestWidget(Widget):
+        def get_content_width(self, container: Size, parent: Size) -> int:
+            assert False, "must not be called"
+
+        def get_content_height(self, container: Size, parent: Size, width: int) -> int:
+            assert False, "must not be called"
+
+    widget = TestWidget()
+    styles = widget.styles
+
     styles.width = 100
     styles.height = 80
     styles.max_width = 40
     styles.max_height = 30
-    one = Fraction(1)
 
-    def get_auto_width(container: Size, parent: Size) -> int:
-        assert False, "must not be called"
-
-    def get_auto_height(container: Size, parent: Size) -> int:
-        assert False, "must not be called"
-
-    box_model = get_box_model(
-        styles, Size(40, 30), Size(80, 24), one, one, get_auto_width, get_auto_height
-    )
+    box_model = widget._get_box_model(Size(40, 30), Size(80, 24), one, one)
     assert box_model == BoxModel(Fraction(40), Fraction(30), Spacing(0, 0, 0, 0))
 
 
 def test_min():
     """Check that min_width and min_height are respected."""
-    styles = Styles()
+
+    one = Fraction(1)
+
+    class TestWidget(Widget):
+        def get_content_width(self, container: Size, parent: Size) -> int:
+            assert False, "must not be called"
+
+        def get_content_height(self, container: Size, parent: Size, width: int) -> int:
+            assert False, "must not be called"
+
+    widget = TestWidget()
+    styles = widget.styles
     styles.width = 10
     styles.height = 5
     styles.min_width = 40
     styles.min_height = 30
-    one = Fraction(1)
 
-    def get_auto_width(container: Size, parent: Size) -> int:
-        assert False, "must not be called"
-
-    def get_auto_height(container: Size, parent: Size) -> int:
-        assert False, "must not be called"
-
-    box_model = get_box_model(
-        styles, Size(40, 30), Size(80, 24), one, one, get_auto_width, get_auto_height
-    )
+    box_model = widget._get_box_model(Size(40, 30), Size(80, 24), one, one)
     assert box_model == BoxModel(Fraction(40), Fraction(30), Spacing(0, 0, 0, 0))