paweld/lazarus
1
0
Fork 0
mirror of https://gitlab.com/freepascal.org/lazarus/lazarus.git synced 2025-04-18 15:09:26 +02:00
Code Issues Packages Projects Releases Wiki Activity

Cocoa: LCL scrolling improvements by Zoë Peterson, issue #39477:

Browse Source 
1. Better handling of hasPreciseScrollingDeltas and SPI_GETWHEELSCROLLINES.  The scrolling in LCL trunk is much too fast and imprecise.  This improves the feel of things using both a mouse wheel and the touchpad.  I don't like having the 15 for average line height hard coded in it, but I haven't seen any cases where it causes problems.

2. In the case where it sees a scroll in both X and Y directions, it filters it in favor of the last scroll direction.  This makes vertical scrolling documents using the touchpad better, since you're less likely to inadvertently scroll horizontally.

3. Msg.WheelDelta is a SmallInt, so this caps the values to High/Low(SmallInt), rather than the underflow/overflow that occurs currently.  That fixes the issue this bug report specifically is about.

(cherry picked from commit 8e10ed53af)
This commit is contained in:
Maxim Ganetsky 2022-01-09 03:02:47 +03:00
parent 0b9a2099dc
commit 5efbbc0f96
2 changed files with 22 additions and 28 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
lcl/interfaces/cocoa/cocoawinapi.inc
View File

@ -1027,7 +1027,7 @@ function TCocoaWidgetSet.SystemParametersInfo(uiAction: DWord; uiParam: DWord;
begin
Result := True;
case uiAction of
SPI_GETWHEELSCROLLLINES: PDword(pvPAram)^ := 3;
SPI_GETWHEELSCROLLLINES: PDword(pvPAram)^ := 1;
SPI_GETWORKAREA:
begin
NSToLCLRect(NSScreen(NSScreen.screens.objectAtIndex(0)).visibleFrame

48
lcl/interfaces/cocoa/cocoawscommon.pas
View File

@ -32,6 +32,7 @@ type
FBoundsReportedToChildren: boolean;
FIsOpaque:boolean;
FIsEventRouting:boolean;
FLastWheelWasHorz:boolean;
protected
function GetHasCaret: Boolean;
procedure SetHasCaret(AValue: Boolean);
@ -1182,12 +1183,8 @@ var
MousePos: NSPoint;
MButton: NSInteger;
bndPt, clPt, srchPt: TPoint;
dx,dy: double;
isPrecise: Boolean;
const
WheelDeltaToLCLY = 1200; // the basic (one wheel-click) is 0.1 on cocoa
WheelDeltaToLCLX = 1200; // the basic (one wheel-click) is 0.1 on cocoa
LCLStep = 120;
scrollDelta: Single;
wheelDelta: Integer;
begin
Result := False; // allow cocoa to handle message
@ -1210,45 +1207,42 @@ begin
Msg.Y := round(clPt.Y);
Msg.State := CocoaModifiersToShiftState(Event.modifierFlags, NSEvent.pressedMouseButtons);
if NSAppKitVersionNumber >= NSAppKitVersionNumber10_7 then
begin
isPrecise := event.hasPreciseScrollingDeltas;
dx := event.scrollingDeltaX;
dy := event.scrollingDeltaY;
end else
begin
isPrecise := false;
dx := event.deltaX;
dy := event.deltaY;
end;
// Some info on event.deltaY can be found here:
// https://developer.apple.com/library/mac/releasenotes/AppKit/RN-AppKitOlderNotes/
// It says that deltaY=1 means 1 line, and in the LCL 1 line is 120
if dy <> 0 then
if (event.scrollingDeltaY <> 0) and
((event.scrollingDeltaX = 0) or not FLastWheelWasHorz) then
begin
Msg.Msg := LM_MOUSEWHEEL;
if isPrecise then
Msg.WheelDelta := Round(dy * LCLStep)
if event.hasPreciseScrollingDeltas then
scrollDelta := event.scrollingDeltaY / 15 // Average line height
else
Msg.WheelDelta := sign(dy) * LCLStep;
scrollDelta := event.scrollingDeltaY;
wheelDelta := round(scrollDelta * 120);
end
else
if dx <> 0 then
if event.scrollingDeltaX <> 0 then
begin
Msg.Msg := LM_MOUSEHWHEEL;
// see "deltaX" documentation.
// on macOS: -1 = right, +1 = left
// on LCL: -1 = left, +1 = right
if isPrecise then
Msg.WheelDelta := Round(-dx * LCLStep)
else
Msg.WheelDelta := sign(-dx) * LCLStep;
wheelDelta := round(-event.scrollingDeltaX * 120);
end
else
// Filter out empty events - See bug 28491
Exit;
// Filter scrolls that affect both X and Y towards whatever the last scroll was
FLastWheelWasHorz := (Msg.Msg = LM_MOUSEHWHEEL);
// Avoid overflow/underflow in message
if wheelDelta > High(SmallInt) then
wheelDelta := High(SmallInt)
else if wheelDelta < Low(SmallInt) then
wheelDelta := Low(SmallInt);
Msg.WheelDelta := wheelDelta;
NotifyApplicationUserInput(Target, Msg.Msg);
Result := DeliverMessage(Msg) <> 0;
end;