data-display-and-selection（数据显示和选择）

Data Display and Selection

Complex data collections — products, files, users, orders, tasks — have no single correct view. Different tasks call for different views. Browsing benefits from grid; comparing details benefits from list or table; bulk management benefits from a dense table with mass actions. Give users the choice.

View Modes

Offer multiple views when the data has both visual and detailed dimensions.

View toggle placement: top-right of the collection, adjacent to sort/filter controls. Use icon buttons with tooltips (grid, list, table). Persist the user's choice in localStorage.

[Filter ▾]  [Sort ▾]          [⊞ Grid]  [☰ List]  [⊟ Table]

On mobile, collapse to the view that works best for the content — grid for visual items, list for text. Do not offer a view toggle on small screens unless both views are genuinely usable.

Selection: Prefer Large Hit Areas

Checkboxes are small targets. Requiring users to hit a 16×16px checkbox to select a row is unnecessary friction — especially on touch devices.

Default: the entire row or card is the selection target.

• Click anywhere on the row → selects the row (background shifts, checkbox checks)
• The checkbox is a visual indicator of selection state, not the only way to select
• Keyboard: Space selects the focused row; Shift+click extends selection; Ctrl/Cmd+click toggles individual items

.row {
  cursor: pointer;
  background: var(--color-surface);
  transition: background 100ms ease-out;
}
.row:hover {
  background: var(--color-grey-50);
}
.row.selected {
  background: var(--color-primary-subtle); /* subtle brand tint */
}

For cards in a grid, the entire card is the selection area — not just a checkbox in the corner.

Selected State Visual Language

Selected items communicate their state through a background colour shift — not just a checkbox tick.

Background: --color-primary-subtle — the brand primary colour heavily desaturated and lightened to ~5–8% opacity. Perceptible but not jarring.

Left border accent (optional): A 3px left border in --color-primary reinforces the selected state for list and table rows.

Checkbox: Checked and filled with --color-primary. The checkbox is a secondary signal, not the primary one.

.row.selected {
  background: var(--color-primary-subtle);    /* e.g. hsl(224, 21%, 94%) */
  border-left: 3px solid var(--color-primary);
}

Do not use a high-contrast or saturated background for selection — it competes with content and makes dense tables hard to read.

Mass Actions

When one or more items are selected, mass actions appear. They disappear when nothing is selected.

Placement: A contextual toolbar that appears at the top of the collection (replacing or supplementing the standard toolbar) when selection is active.

[✓ 3 selected]  [Delete]  [Archive]  [Export]  [Move to ▾]  [× Clear]

• Lead with the selection count: "3 selected" — confirms the scope before any action
• Show only actions applicable to the selection — if some actions require a single item, disable them for multi-select
• "Clear" deselects everything and dismisses the toolbar
• Destructive mass actions (Delete) always trigger a confirm dialog naming the count: "Delete 3 projects? This cannot be undone."

Select all: A checkbox in the table header selects all items on the current page. A secondary action "Select all 247" extends to the full dataset.

[☑ Select all on page]  →  [Select all 247 results]

Sorting and Filtering

Column sorting (table view)

• Click a column header to sort ascending; click again for descending; third click clears sort
• Active sort column shows a directional arrow (↑ ↓)
• Only sortable columns are clickable — non-sortable columns have no hover state on header

Filters

• Persistent filters belong in a sidebar or filter bar above the collection
• Active filters should be visible as chips/tags that can be individually removed
• "Clear all filters" removes all active filters in one action
• Filter count badge on the filter button when filters are active: Filter (3)

Empty states

• No results from filter: "No results for these filters. [Clear filters]" — do not show a generic empty state
• Genuinely empty collection: show a call to action for the first item: "No projects yet. [Create project]"

Table-Specific Patterns

Sticky header

Table column headers stick to the top when scrolling vertically — users must always be able to see what each column means.

Sticky first column

For wide tables that scroll horizontally, the first column (row identifier — name, ID) sticks to the left.

Row actions

Per-row actions (Edit, Delete, View) appear on hover in the rightmost column. Do not show them at rest — they add visual noise.

[Name]  [Status]  [Date]  [Amount]          ← at rest
[Name]  [Status]  [Date]  [Amount]  [Edit] [⋯]  ← on hover

Column resize and reorder

For enterprise data tables: allow columns to be resized by dragging the header border, and reordered by dragging the header. Persist the layout.

Review Checklist

• Is a view mode toggle offered when data has both visual and detail dimensions?
• Is the user's preferred view persisted across sessions?
• Is the entire row or card the selection hit area — not just the checkbox?
• Does selected state use a subtle background colour shift (--color-primary-subtle)?
• Does a mass action toolbar appear when items are selected, showing the selection count?
• Do destructive mass actions require a confirm dialog naming the item count?
• Does "Select all" work per page, with an option to extend to the full dataset?
• Are active filters visible as removable chips?
• Does the empty state differ between "no results" and "genuinely empty"?
• Are per-row actions shown on hover only, not at rest?
• Is the table header sticky when the table scrolls vertically?