Issue 803 - Fix scroll alignment on scroll/hover, edit, navigate

.Rbuildignore

@@ -20,7 +20,7 @@ demo/.*\.js
 demo/.*\.html
 demo/.*\.css
 
-# ignore python files/folders
+# ignore Python files/folders
 setup.py
 usage.py
 setup.py

src/dash-table/components/ControlledTable/index.tsx

@@ -385,22 +385,22 @@ export default class ControlledTable extends PureComponent<ControlledTableProps>
                 // Force first column containers width to match visible portion of table
                 r0c0.style.width = `${lastFixedTdRight}px`;
                 r1c0.style.width = `${lastFixedTdRight}px`;
-
-                if (!cycle) {
-                    // Force second column containers width to match visible portion of table
-                    const firstVisibleTd = r1c1.querySelector(`tr:first-of-type > *:nth-of-type(${fixed_columns + 1})`);
-                    if (firstVisibleTd) {
-                        const r1c1FragmentBounds = r1c1.getBoundingClientRect();
-                        const firstTdBounds = firstVisibleTd.getBoundingClientRect();
-
-                        const width = firstTdBounds.left - r1c1FragmentBounds.left;
-                        r0c1.style.marginLeft = `-${width}px`;
-                        r1c1.style.marginLeft = `-${width}px`;
-                    }
-                }
             }
         }
 
+        // Force second column containers width to match visible portion of table
+        const firstVisibleTd = r1c1.querySelector(`tr:first-of-type > *:nth-of-type(${fixed_columns + 1})`);
+        if (firstVisibleTd) {
+            const r1c1FragmentBounds = r1c1.getBoundingClientRect();
+            const firstTdBounds = firstVisibleTd.getBoundingClientRect();
+
+            const width = firstTdBounds.left - r1c1FragmentBounds.left;
+            const { r1 } = this.refs as Refs;
+
+            r0c1.style.marginLeft = `-${width + r1.scrollLeft}px`;
+            r1c1.style.marginLeft = `-${width}px`;
+        }
+
         if (!cycle) {
             const currentWidth = parseInt(currentTableWidth, 10);
             const nextWidth = parseInt(getComputedStyle(r1c1Table).width, 10);

tests/selenium/test_scrolling.py

@@ -4,9 +4,40 @@
 
 import pandas as pd
 import pytest
+from selenium.webdriver.common.keys import Keys
 
 df = pd.read_csv("https://raw.githubusercontent.com/plotly/datasets/master/solar.csv")
 
+base_props = dict(
+    id="table",
+    columns=[{"name": i, "id": i} for i in df.columns],
+    row_selectable="single",
+    row_deletable=True,
+    data=df.to_dict("records"),
+    editable=True,
+    fixed_rows={"headers": True, "data": 1},
+    style_cell=dict(width=150),
+    style_table=dict(width=500),
+)
+
+
+def get_margin(test):
+    return test.driver.execute_script(
+        "return parseFloat(getComputedStyle(document.querySelector('#table .cell-0-1')).marginLeft);"
+    )
+
+
+def get_scroll(test):
+    return test.driver.execute_script(
+        "return document.querySelector('#table .row-1').scrollLeft;"
+    )
+
+
+def scroll_by(test, value):
+    return test.driver.execute_script(
+        "document.querySelector('#table .row-1').scrollBy({}, 0);".format(value)
+    )
+
 
 @pytest.mark.parametrize(
     "fixed_rows",
@@ -24,17 +55,6 @@
     "ops", [dict(), dict(row_selectable="single", row_deletable=True)]
 )
 def test_scrol001_fixed_alignment(test, fixed_rows, fixed_columns, ops):
-    base_props = dict(
-        id="table",
-        columns=[{"name": i, "id": i} for i in df.columns],
-        row_selectable="single",
-        row_deletable=True,
-        data=df.to_dict("records"),
-        fixed_rows={"headers": True, "data": 1},
-        style_cell=dict(width=150),
-        style_table=dict(width=500),
-    )
-
     props = {**base_props, **fixed_rows, **fixed_columns, **ops}
 
     app = dash.Dash(__name__)
@@ -48,32 +68,64 @@ def test_scrol001_fixed_alignment(test, fixed_rows, fixed_columns, ops):
     fixed_width = test.driver.execute_script(
         "return parseFloat(getComputedStyle(document.querySelector('#table .cell-0-0')).width) || 0;"
     )
-    margin_left = test.driver.execute_script(
-        "return parseFloat(getComputedStyle(document.querySelector('#table .cell-0-1')).marginLeft);"
-    )
 
-    assert -margin_left == fixed_width
+    assert -get_margin(test) == fixed_width
+
+    scroll_by(test, 200)
 
-    test.driver.execute_script(
-        "document.querySelector('#table .row-1').scrollBy(200, 0);"
+    wait.until(
+        lambda: -get_margin(test) == fixed_width + 200, 3,
     )
 
+    scroll_by(test, -200)
+
     wait.until(
-        lambda: -test.driver.execute_script(
-            "return parseFloat(getComputedStyle(document.querySelector('#table .cell-0-1')).marginLeft);"
-        )
-        == fixed_width + 200,
-        3,
+        lambda: -get_margin(test) == fixed_width, 3,
     )
 
-    test.driver.execute_script(
-        "document.querySelector('#table .row-1').scrollBy(-200, 0);"
+
+@pytest.mark.parametrize(
+    "fixed_rows",
+    [dict(fixed_rows=dict(headers=True)), dict(fixed_rows=dict(headers=True, data=1))],
+)
+@pytest.mark.parametrize(
+    "fixed_columns",
+    [
+        dict(),
+        dict(fixed_columns=dict(headers=True)),
+        dict(fixed_columns=dict(headers=True, data=1)),
+    ],
+)
+@pytest.mark.parametrize(
+    "ops", [dict(), dict(row_selectable="single", row_deletable=True)]
+)
+def test_scrol002_edit_navigate(test, fixed_rows, fixed_columns, ops):
+    props = {**base_props, **fixed_rows, **fixed_columns, **ops}
+
+    app = dash.Dash(__name__)
+    app.layout = DataTable(**props)
+
+    test.start_server(app)
+
+    target = test.table("table")
+    assert target.is_ready()
+
+    fixed_width = test.driver.execute_script(
+        "return parseFloat(getComputedStyle(document.querySelector('#table .cell-0-0')).width) || 0;"
     )
 
+    scroll_by(test, 200)
+
+    # alignment is ok after editing a cell
+    target.cell(0, 3).click()
+    test.send_keys("abc" + Keys.ENTER)
+
+    wait.until(lambda: -get_margin(test) == fixed_width + get_scroll(test), 3)
+
+    # alignment is ok after navigating
+    test.send_keys(Keys.ARROW_DOWN)
+    test.send_keys(Keys.ARROW_UP)
+
     wait.until(
-        lambda: -test.driver.execute_script(
-            "return parseFloat(getComputedStyle(document.querySelector('#table .cell-0-1')).marginLeft);"
-        )
-        == fixed_width,
-        3,
+        lambda: -get_margin(test) == fixed_width + get_scroll(test), 3,
     )