'border' set at widget creation.

Author: Zerline

ipywidgets/widgets/widget_layout.py

@@ -79,6 +79,14 @@ class Layout(Widget):
     grid_column = Unicode(None, allow_none=True, help="The grid-column CSS attribute.").tag(sync=True)
     grid_area = Unicode(None, allow_none=True, help="The grid-area CSS attribute.").tag(sync=True)
 
+    def __init__(self, **kwargs):
+        """Public constructor"""
+        super().__init__(**kwargs)
+        if self.border is not None:
+            for side in ['top', 'right', 'bottom', 'left']:
+                if getattr(self, "border_" + side) is None:
+                    setattr(self, "border_" + side, self.border)
+
 
 class LayoutTraitType(Instance):
 

tests/test_borders.ipynb

@@ -15,7 +15,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "t1 = Text(\"text input\")\n",
+    "t1 = Text(\"text input\", layout=Layout(width=\"80px\", border=\"1px dashed red\"))\n",
     "b1 = Button(description=\"button\")\n",
     "HBox((t1,b1))"
    ]
@@ -27,7 +27,6 @@
    "outputs": [],
    "source": [
     "b1.layout.border = \"2px solid yellow\"\n",
-    "t1.layout.border = \"1px dashed red\"\n",
     "t1.layout.border_left = \"5px dotted blue\"\n",
     "b1.layout.border_right = \"2px dotted blue\""
    ]
@@ -39,7 +38,7 @@
    "outputs": [],
    "source": [
     "t2 = Text(\"text input\")\n",
-    "b2 = ToggleButton(description=\"toggle button\")\n",
+    "b2 = ToggleButton(description=\"toggle button\", layout=Layout(width=\"200px\", border_left=\"2px solid yellow\"))\n",
     "HBox((t2,b2))"
    ]
   },
@@ -51,7 +50,6 @@
    "source": [
     "t2.layout.border_left = \"5px dotted blue\"\n",
     "b2.layout.border_right = \"2px dotted blue\"\n",
-    "b2.layout.border = \"2px solid yellow\"\n",
     "t2.layout.border = \"1px dashed red\""
    ]
   },
@@ -61,10 +59,9 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "t1.style.border_top = \"5px solid green\"\n",
-    "b1.style.border = \"1px solid purple\"\n",
-    "t2.style.border_top = \"5px solid green\"\n",
-    "b2.style.border = \"1px solid purple\""
+    "t1.layout.border_top = \"5px solid green\"\n",
+    "b1.layout.border = \"1px solid purple\"\n",
+    "t2.layout.border_right = \"5px double skyblue\""
    ]
   }
  ],