Add RTL support

[xoascf]

Problems (when "flow_direction" is set to RightToLeft):

• Notification balloons do not point to the correct icon in the notification area Fixed in dff8606 (Add RTL support #132 (comment))
• Start button may need some space on the right side (or use a space character " " in translations)
  Some original translations of themes (like Windows XP), use spaces in the text of the Start button for some RTL languages, so it's probably ok to use them as well
• Taskbar context menu does not display correctly or update its width when switching from RTL language to LTR language
  Previously fixed in 16dc95e, now using the suggested approach in efa8823

Should be working now. Languages requiring this feature will be added soon.

[xoascf]

@dremin, any idea how to fix the notification balloon positions for RTL languages? I haven't figured out how...

[dremin]

@xoascf I can take a look. Do you know how I can test this on an English installation of Windows?

[xoascf]

@xoascf I can take a look. Do you know how I can test this on an English installation of Windows?

Yeah, there should be no difference, the changes here are only visual.

[dremin]

I have balloons positioning correctly. Here are the changes I made:

• NotifyBalloon.xaml.cs:PlacePopup needs conditions for FlowDirection for Top, Left, and Bottom edge cases

public CustomPopupPlacement[] PlacePopup(Size popupSize, Size targetSize, Point offset)
{
    CustomPopupPlacement placement;

    DpiScale dpiScale = VisualTreeHelper.GetDpi(this);

    switch ((AppBarEdge)Settings.Instance.Edge)
    {
        case AppBarEdge.Top:
            if (FlowDirection == FlowDirection.LeftToRight)
            {
                placement = new CustomPopupPlacement(new Point((popupSize.Width * -1) + (offset.X * dpiScale.DpiScaleX),
                    targetSize.Height + (offset.Y * dpiScale.DpiScaleY)),
                    PopupPrimaryAxis.Horizontal);
            }
            else
            {
                placement = new CustomPopupPlacement(new Point(-1 * offset.X * dpiScale.DpiScaleX,
                    targetSize.Height + (offset.Y * dpiScale.DpiScaleY)),
                    PopupPrimaryAxis.Horizontal);
            }
            break;
        case AppBarEdge.Left:
            placement = new CustomPopupPlacement(new Point(offset.X * dpiScale.DpiScaleX - (FlowDirection == FlowDirection.LeftToRight ? 0 : targetSize.Width),
                (popupSize.Height * -1) + (offset.Y * dpiScale.DpiScaleY)),
                PopupPrimaryAxis.Horizontal);
            break;
        case AppBarEdge.Right:
            placement = new CustomPopupPlacement(new Point((popupSize.Width * -1) + (offset.X * dpiScale.DpiScaleX),
                (popupSize.Height * -1) + (offset.Y * dpiScale.DpiScaleY)),
                PopupPrimaryAxis.Horizontal);
            break;
        default:
            // bottom taskbar
            if (FlowDirection == FlowDirection.LeftToRight)
            {
                placement = new CustomPopupPlacement(new Point((popupSize.Width * -1) + (offset.X * dpiScale.DpiScaleX),
                    (popupSize.Height * -1) + (offset.Y * dpiScale.DpiScaleY)),
                    PopupPrimaryAxis.Horizontal);
            }
            else
            {
                placement = new CustomPopupPlacement(new Point(-1 * offset.X * dpiScale.DpiScaleX,
                    (popupSize.Height * -1) + (offset.Y * dpiScale.DpiScaleY)),
                    PopupPrimaryAxis.Horizontal);
            }
            break;
    }

    return new CustomPopupPlacement[] { placement };
}

• System.xaml: The NotifyBalloon template triggers need an additional FlowDirection condition for the Left edge case (and a corresponding one for the Right edge case) to fix arrow positions.

<ControlTemplate.Triggers>
    <MultiDataTrigger>
        <MultiDataTrigger.Conditions>
            <Condition Binding="{Binding Path=AppBarEdge, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type Window}}}"
                        Value="Left" />
            <Condition Binding="{Binding Path=FlowDirection, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type Window}}}"
                        Value="LeftToRight" />
        </MultiDataTrigger.Conditions>
        <MultiDataTrigger.Setters>
            <Setter TargetName="Arrow"
                    Property="Data"
                    Value="M 0,0 V 20 l 20,-20" />
            <Setter TargetName="Arrow"
                    Property="HorizontalAlignment"
                    Value="Left" />
        </MultiDataTrigger.Setters>
    </MultiDataTrigger>
    <MultiDataTrigger>
        <MultiDataTrigger.Conditions>
            <Condition Binding="{Binding Path=AppBarEdge, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type Window}}}"
                        Value="Right" />
            <Condition Binding="{Binding Path=FlowDirection, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type Window}}}"
                        Value="RightToLeft" />
        </MultiDataTrigger.Conditions>
        <MultiDataTrigger.Setters>
            <Setter TargetName="Arrow"
                    Property="Data"
                    Value="M 0,0 V 20 l 20,-20" />
            <Setter TargetName="Arrow"
                    Property="HorizontalAlignment"
                    Value="Left" />
        </MultiDataTrigger.Setters>
    </MultiDataTrigger>
    <DataTrigger Binding="{Binding Path=AppBarEdge, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type Window}}}"
                    Value="Top">
        <DataTrigger.Setters>
            <Setter TargetName="Border"
                    Property="DockPanel.Dock"
                    Value="Bottom" />
            <Setter TargetName="Arrow"
                    Property="Data"
                    Value="M 0,20 l 20,-20 v 20" />
            <Setter TargetName="Arrow"
                    Property="DockPanel.Dock"
                    Value="Top" />
            <Setter TargetName="Arrow"
                    Property="Margin"
                    Value="13,0,13,-2" />
        </DataTrigger.Setters>
    </DataTrigger>
</ControlTemplate.Triggers>

[dremin]

Can you remove this vestige? Once done it will be good to merge!