+ float newYPosition = Clamp( scrollPostPosition.y, ( mDomainMax.y + size.y ) - mMaxOvershoot.y, mDomainMin.y + mMaxOvershoot.y );
+ if( ( newYPosition < scrollPostPosition.y - Math::MACHINE_EPSILON_1 )
+ || ( newYPosition > scrollPostPosition.y + Math::MACHINE_EPSILON_1 ) )
+ {
+ mPrePosition.y = newYPosition;
+ mLocalStart.y = panPosition.y;
+ }
+ scrollPostPosition.y = newYPosition;
+ }
+
+ // If we are using a fixed ruler in a particular axis, limit the maximum pages scrolled on that axis.
+ if( mFixedRulerX || mFixedRulerY )
+ {
+ // Here we limit the maximum amount that can be moved from the starting position of the gesture to one page.
+ // We do this only if we have a fixed ruler (on that axis) and the mode is enabled.
+ // Note: 1.0f is subtracted to keep the value within one page size (otherwise we stray on to the page after).
+ // Note: A further 1.0f is subtracted to handle a compensation that happens later within the flick handling code in SnapWithVelocity().
+ // When a flick is completed, an adjustment of 1.0f is sometimes made to allow for the scenario where:
+ // A flick finishes before the update thread has advanced the scroll position past the previous snap point.
+ Vector2 pageSizeLimit( size.x - ( 1.0f + 1.0f ), size.y - ( 1.0f - 1.0f ) );
+ Vector2 minPosition( mStartPosition.x - pageSizeLimit.x, mStartPosition.y - pageSizeLimit.y );
+ Vector2 maxPosition( mStartPosition.x + pageSizeLimit.x, mStartPosition.y + pageSizeLimit.y );
+
+ if( mFixedRulerX )
+ {
+ scrollPostPosition.x = Clamp( scrollPostPosition.x, minPosition.x, maxPosition.x );
+ }
+ if( mFixedRulerY )
+ {
+ scrollPostPosition.y = Clamp( scrollPostPosition.y, minPosition.y, maxPosition.y );
+ }