WidgetScrollController class
A simple ScrollController for use with SingleChildScrollView, ScrollView, and ListView.
Tracks viewport dimension, content extent, and scroll offset. The viewport render object calls updateMetrics after layout; the widget state calls scrollBy / jumpTo in response to user input.
- Implemented types
Constructors
Properties
- contentExtent → int
-
Total content extent in rows.
no setteroverride
- hashCode → int
-
The hash code for this object.
no setterinherited
- hasSelection → bool
-
Whether a selection is currently active (start and end are set).
no setter
- maxOffset → int
-
Maximum scroll offset.
no setteroverride
- offset → int
-
Current scroll offset in rows.
no setteroverride
- runtimeType → Type
-
A representation of the runtime type of the object.
no setterinherited
- scrollPercent → double
-
Scroll percentage in the range
0, 1.no setteroverride - selecting → bool
-
Whether a drag-selection is in progress.
no setter
- selectionEnd → ({int x, int y})?
-
The selection end point, or null.
no setter
- selectionStart → ({int x, int y})?
-
The selection start point, or null.
no setter
- thumbDragActive → bool
-
Whether an attached scrollbar thumb drag is currently active.
no setter
- viewportExtent → int
-
Visible viewport extent in rows.
no setteroverride
Methods
-
addListener(
void listener()) → void -
Adds a listener that fires when the scroll offset changes.
override
-
clearSelection(
) → void - Clears the current selection and notifies listeners.
-
getSelectedText(
List< String> lines) → String -
Extracts the selected text from rendered content
lines. -
jumpTo(
int offset) → bool -
Jumps to an absolute offset. Returns true if the offset changed.
override
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a nonexistent method or property is accessed.
inherited
-
removeListener(
void listener()) → void -
Removes a previously added listener.
override
-
scrollBy(
int delta) → bool -
Scrolls by a delta. Returns true if the offset changed.
override
-
setSelection(
{required ({int x, int y}) start, required ({int x, int y}) end}) → void - Sets the selection start and end, and notifies listeners.
-
setThumbDragActive(
bool active) → void - Marks whether an attached scrollbar thumb drag is active.
-
toString(
) → String -
A string representation of this object.
inherited
-
updateMetrics(
{required int viewportExtent, required int contentExtent}) → bool - Updates metrics after layout. Returns true if offset was clamped.
Operators
-
operator ==(
Object other) → bool -
The equality operator.
inherited