using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Controls.Primitives;
using System.Windows.Media;
namespace MmdPdf
{
// Configurable sidebar placement (left or right). The layout uses three columns in
// MainContentGrid: one sized sidebar column, a 6px splitter, and a star document column.
// ApplySidebarSide swaps which outer column is the sidebar and repoints _sidebarCol so the
// existing collapse / resize logic keeps working unchanged.
public partial class MainWindow
{
// Document on the right (sidebar left) -> 8px inset on the right; mirrored when the sidebar
// moves. Top and bottom stay 0: PaneShadow is Direction 270 and draws outside the element's
// bounds without taking layout space, so a bottom gap would be real padding lifting the
// card off the footer, not room for the shadow (KillerShell's ResultsPane comment).
//
// The sidebar side is 0, not a pull-back. That 6px column is a plain gap - KillerShell's
// TreeGapCol - because the grip lives inside the sidebar, so nothing sits there and the
// grain layer paints it like the rest of the surface.
// Top is -1, KillerShell's ResultsPane margin verbatim: the card's own top border tucks
// UNDER the tab band, which is opaque, so the active tab and the pane read as one surface
// instead of being split by a hairline under the active tab. With no tabs open the band is
// collapsed and the -1 just eats a pixel against the toolbar.
private Thickness DocPaneInsetMargin()
{
// This is layout geometry, not a palette value. Keep the zero-inset exception scoped
// to 98SE so it cannot leak into the rounded themes after a live theme switch.
double inset = Services.ThemeManager.Current == Services.Theme.SE98 ? 0 : 8;
return _sidebarRight ? new Thickness(inset, -1, 0, 0)
: new Thickness(0, -1, inset, 0);
}
// The grip drives SidebarCol's width directly (see the XAML comment). Dragging toward the
// document grows the sidebar when it is on the left and shrinks it when on the right, so
// the delta is signed by side. Clamped to the column's own Min/MaxWidth, which the collapse
// and outline/pages modes already maintain, so this cannot drag past a readable minimum.
private void SidebarGrip_DragStarted(object sender, DragStartedEventArgs e)
=> OnSidebarSplitterPress();
private void SidebarGrip_DragCompleted(object sender, DragCompletedEventArgs e)
=> OnSidebarResized();
private void SidebarGrip_DragDelta(object sender, DragDeltaEventArgs e)
{
if (_sidebarCol == null) return;
double w = _sidebarCol.ActualWidth + (_sidebarRight ? -e.HorizontalChange : e.HorizontalChange);
double min = _sidebarCol.MinWidth > 0 ? _sidebarCol.MinWidth : SbPx(24);
double max = double.IsPositiveInfinity(_sidebarCol.MaxWidth) ? double.MaxValue : _sidebarCol.MaxWidth;
_sidebarCol.Width = new GridLength(Math.Max(min, Math.Min(max, w)));
OnSidebarSplitterMove(sender, new System.Windows.Input.MouseEventArgs(
System.Windows.Input.Mouse.PrimaryDevice, Environment.TickCount)
{ RoutedEvent = System.Windows.Input.Mouse.MouseMoveEvent });
}
// A Border with a CornerRadius does not clip its child, so the canvas, the grain and the
// page itself all square the card's corners straight back off. Radius 5 = the card's 6
// less its 1px border, which is where the inner edge of the curve actually falls.
// internal: PdfViewer's XAML binds this and forwards to it.
internal void DocPane_SizeChanged(object sender, SizeChangedEventArgs e)
{
if (sender is not FrameworkElement el) return;
double outer = TryFindResource("PanelCornerRadius") is CornerRadius cr ? cr.TopLeft : 6;
double inner = Math.Max(0, outer - 1);
el.Clip = new RectangleGeometry(new Rect(0, 0, el.ActualWidth, el.ActualHeight), inner, inner);
}
// Clip the tab-strip shadow gradient to the document column so it never falls over the
// sidebar (on whichever side the sidebar sits).
private void UpdateTabStripFade()
{
// The tab-strip gradient band spans the splitter column + document column. BOTH ends are
// feathered. The document-facing end used to keep a hard stop on the reasoning that it
// was the window edge and should be crisp; with the split it is not the window edge at
// all, it is a seam in the middle of the window, and it read as a solid vertical line
// rising out of the pane. A shadow with a visible end is not a shadow.
if (TabStripFade != null)
{
TabStripFade.Margin = new Thickness(0);
double w = TabStripFade.ActualWidth;
if (w > 0)
{
double f = Math.Min(0.5, 32.0 / w); // wider (~32px) feather than the footer - the top
// shadow is darker, so a 15px fade still read as a
// hard vertical edge near the sidebar corner
var mask = new LinearGradientBrush { StartPoint = new Point(0, 0), EndPoint = new Point(1, 0) };
// Same ramp at both ends. The sidebar-facing side keeps the wider feather it
// already had; the document-facing side gets a shorter one, enough to kill the
// hard line without eating into the strip.
double fDoc = Math.Min(0.25, 14.0 / w);
double fNear = _sidebarRight ? fDoc : f;
double fFar = _sidebarRight ? f : fDoc;
mask.GradientStops.Add(new GradientStop(Colors.Transparent, 0));
mask.GradientStops.Add(new GradientStop(Colors.White, fNear));
mask.GradientStops.Add(new GradientStop(Colors.White, 1 - fFar));
mask.GradientStops.Add(new GradientStop(Colors.Transparent, 1));
TabStripFade.OpacityMask = mask;
}
else TabStripFade.OpacityMask = null;
}
UpdateFooterFade();
}
// Keep the portable install action centered on the real A/B boundary. The old footer centered
// the PORTABLE + button group across the whole status bar; after removing the label that left
// no relationship between the button and the pane divider, especially after either pane was
// resized. In a single-pane window, the document pane's center is the natural fallback.
private void UpdateFooterFade()
{
if (_portableBadge is null || SplitHost is null || SplitHost.ActualWidth <= 0) return;
if (_portableBadge.Parent is not Visual footerGrid) return;
try
{
double hostLeft = SplitHost.TransformToVisual(footerGrid)
.Transform(new Point(0, 0)).X;
double anchor = _isSplit && PaneBCol.ActualWidth > 0
? hostLeft + PaneACol.ActualWidth + PaneGutterCol.ActualWidth / 2
: hostLeft + SplitHost.ActualWidth / 2;
double width = _portableBadge.ActualWidth;
if (width <= 0)
{
_portableBadge.Measure(new Size(double.PositiveInfinity, double.PositiveInfinity));
width = _portableBadge.DesiredSize.Width;
}
_portableBadge.Margin = new Thickness(Math.Round(anchor - width / 2), 0, 0, 0);
// Cap the status line so it ellipsizes before reaching the Install action - at a
// small window width a long status painted straight through the button.
if (StatusText is not null)
{
if (_portableBadge.Visibility == Visibility.Visible)
{
double statusLeft = StatusText.TransformToVisual(footerGrid)
.Transform(new Point(0, 0)).X;
double badgeLeft = anchor - width / 2;
StatusText.MaxWidth = Math.Max(0, badgeLeft - statusLeft - 8);
}
else StatusText.MaxWidth = double.PositiveInfinity;
}
}
catch (InvalidOperationException)
{
// The two elements are briefly disconnected during startup/theme reconstruction.
// A queued layout refresh retries once they share the live visual tree again.
}
}
// The collapse arrow points toward where the page-list content goes when toggled, which
// depends on both the side and the collapsed state.
private void UpdateSidebarToggleGlyph()
{
if (_sidebarToggleBtn == null) return;
bool pointLeft = _sidebarRight ? _sidebarCollapsed : !_sidebarCollapsed;
_sidebarToggleBtn.Content = pointLeft ? "" : ""; // ChevronLeft / ChevronRight
}
private void SelectSidebarSide(bool right)
{
if (right == _sidebarRight) return; // no change (e.g. picking the side it's already on)
_sidebarRight = right;
App.SetSetting("SidebarSide", right ? "Right" : "Left");
ApplySidebarSide();
}
// Shift+F9 (pairs with F9, the sidebar collapse toggle).
private void ToggleSidebarSide() => SelectSidebarSide(!_sidebarRight);
// ── Page-list edge fades - KillerShell's transparent-content mask ──
// Each edge fades only while there is a row past it. PageList has no horizontal scrollbar,
// so KillerShell's narrow scrollbar-restoration stops are not needed here.
/// Called once from the window ctor, beside InitSplitPanes.
private void WirePageListEdgeFades()
{
// ScrollChanged bubbles, so the ListBox's inner ScrollViewer is reached without
// having to dig it out of the template first. Loaded and SizeChanged cover the
// passes where nothing scrolled but the extent moved (reseat, thumbnail load).
PageList.AddHandler(ScrollViewer.ScrollChangedEvent,
new ScrollChangedEventHandler((_, _) => SyncPageListEdgeFades()));
PageList.SizeChanged += (_, _) => SyncPageListEdgeFades();
PageList.Loaded += (_, _) => SyncPageListEdgeFades();
}
private const double PageListTopFadePx = 18;
private const double PageListBottomFadePx = 22;
private void SyncPageListEdgeFades()
{
var sv = FindSidebarDescendant(PageList);
if (sv == null || PageListFadeHost == null) return;
double height = PageListFadeHost.ActualHeight;
if (height <= 1) return;
// Reveal the actual sidebar underneath; never paint a theme-colored strip over it.
// EdgeFadeOpacity is zero only in 98SE and one in every other theme.
double fade = TryFindResource("EdgeFadeOpacity") is double value ? value : 1.0;
double top = EdgeFadeRamp(sv.VerticalOffset, PageListTopFadePx) * fade;
double bottom = EdgeFadeRamp(
sv.ExtentHeight - sv.ViewportHeight - sv.VerticalOffset,
PageListBottomFadePx) * fade;
PageListFadeTopOuter.Color = FadeMaskAlpha(1 - top);
PageListFadeBottomOuter.Color = FadeMaskAlpha(1 - bottom);
PageListFadeTopInner.Offset = Math.Min(0.45, PageListTopFadePx / height);
PageListFadeBottomInner.Offset = Math.Max(0.5, 1 - PageListBottomFadePx / height);
}
private static double EdgeFadeRamp(double distance, double depth) =>
Math.Min(1, Math.Max(0, distance) / depth);
private static Color FadeMaskAlpha(double opacity) =>
Color.FromArgb(
(byte)Math.Round(Math.Min(1, Math.Max(0, opacity)) * 255),
0, 0, 0);
private static T? FindSidebarDescendant(DependencyObject root) where T : DependencyObject
{
for (int i = 0; i < System.Windows.Media.VisualTreeHelper.GetChildrenCount(root); i++)
{
var c = System.Windows.Media.VisualTreeHelper.GetChild(root, i);
if (c is T t) return t;
var deeper = FindSidebarDescendant(c);
if (deeper != null) return deeper;
}
return null;
}
private void ApplySidebarSide()
{
// SplitHost, NOT Viewer. Since the split landed, the element that sits in
// MainContentGrid is the SPLIT HOST - Viewer is one of its children. Setting
// Grid.Column on Viewer therefore moved pane A into SplitHost's column 2, which is
// PaneBCol and is ZERO WIDTH while unsplit, so the document rendered into a pane with
// no width and the whole content area went blank. Same for the margin below: the 8px
// gutter to the window edge belongs to the host, not to one pane.
//
// Do NOT look up TabStripBorder / TabScroll here: those elements live inside PdfViewer,
// so FindName cannot see them (a UserControl is its own namescope and FindName returns
// null SILENTLY). They would only re-span the band across the splitter column, which is
// meaningless when each strip lives inside its own pane and spans it exactly.
if (FindName("SidebarCol") is not ColumnDefinition sidebarColDef ||
FindName("DocCol") is not ColumnDefinition docColDef ||
FindName("SidebarOuterGrid") is not Grid sbOuter ||
FindName("SidebarBorder") is not Border sbContent ||
FindName("SidebarToggleStrip") is not Border sbToggle ||
SplitHost is not FrameworkElement docPane ||
FindName("SbContentCol") is not ColumnDefinition sbContentCol ||
FindName("SbToggleCol") is not ColumnDefinition sbToggleCol)
return;
// Carry the sized column's current width across a flip (24px when collapsed, else the
// user's width). A star length means it isn't the sized column yet, so fall back.
GridLength sized = _sidebarCollapsed
? new GridLength(SbPx(24))
: (_sidebarCol != null && _sidebarCol.Width.GridUnitType == GridUnitType.Pixel)
? _sidebarCol.Width
: new GridLength(SbPx(180));
double maxW = SbPx(_sidebarShowingOutlines ? SidebarMaxOutlines : SidebarMaxPages);
if (!_sidebarRight)
{
// Sidebar on the LEFT (column 0); document fills column 2.
sidebarColDef.MinWidth = SbPx(_sidebarCollapsed ? 24 : SidebarMinOpen); sidebarColDef.MaxWidth = maxW; sidebarColDef.Width = sized;
docColDef.MinWidth = 0; docColDef.MaxWidth = double.PositiveInfinity;
docColDef.Width = new GridLength(1, GridUnitType.Star);
Grid.SetColumn(sbOuter, 0);
Grid.SetColumn(docPane, 2);
_sidebarCol = sidebarColDef;
// Toggle strip faces the document: right edge of the sidebar.
sbContentCol.Width = new GridLength(1, GridUnitType.Star);
sbToggleCol.Width = new GridLength(24, GridUnitType.Pixel);
Grid.SetColumn(sbContent, 0);
Grid.SetColumn(sbToggle, 1);
}
else
{
// Sidebar on the RIGHT (column 2); document fills column 0.
docColDef.MinWidth = SbPx(_sidebarCollapsed ? 24 : SidebarMinOpen); docColDef.MaxWidth = maxW; docColDef.Width = sized;
sidebarColDef.MinWidth = 0; sidebarColDef.MaxWidth = double.PositiveInfinity;
sidebarColDef.Width = new GridLength(1, GridUnitType.Star);
Grid.SetColumn(sbOuter, 2);
Grid.SetColumn(docPane, 0);
_sidebarCol = docColDef;
// Toggle strip faces the document: left edge of the sidebar (inner column 0). The
// inner column defs are fixed in position, so size them by position, not by name.
sbContentCol.Width = new GridLength(24, GridUnitType.Pixel); // inner col 0 -> toggle
sbToggleCol.Width = new GridLength(1, GridUnitType.Star); // inner col 1 -> content
Grid.SetColumn(sbToggle, 0);
Grid.SetColumn(sbContent, 1);
}
// The splitter's edge-line and the SidebarShadow gradient were both handled here. The
// splitter draws a single centered line now, which is symmetric and so needs no side
// handling, and the fake elevation gradient is gone - DocPaneBorder casts a real
// PaneShadow on all four sides. (2026-07-31.)
// The DocTopAccent / DocBottomAccent repositioning was here. Those two 1px rules are
// gone with the squared layout - the card carries its own border on all four sides now,
// so there is nothing left to bridge to the toolbar and footer. (2026-07-31.)
// The document card's 8px inset always sits on its OUTER edge - the window side, away
// from the splitter - so the gap reads as a margin off the window rather than a gutter
// between the pane and the sidebar. Full screen clears the margin, so leave it alone
// there; ApplyFullScreen restores it from this same helper on exit.
// The grip rides the CONTENT column and faces the rail, so it always sits on the list's
// inner lip: right edge with the sidebar on the left, left edge with it on the right.
if (FindName("SidebarSplitter") is Thumb grip)
{
Grid.SetColumn(grip, _sidebarRight ? 1 : 0);
grip.HorizontalAlignment = _sidebarRight ? HorizontalAlignment.Left
: HorizontalAlignment.Right;
}
// The shadow caster is inside the PdfViewer control, so moving the control moves both -
// one less thing that can drift out of alignment than a separate grid child that has to
// be moved in step with the pane.
if (!_fullScreen)
{
// docPane is SplitHost, so this one margin now insets BOTH panes from the window
// edge together, which is what the 8px gutter always meant.
docPane.Margin = DocPaneInsetMargin();
// No tab-band or TabBarRing margins here. Those exist only to stop a window-level
// band overhanging the card's rounded outer corner, where the band runs the full
// width while the card is inset 8px. Each strip is inside its own pane and spans
// exactly that pane, so the band and the card share an edge by construction.
}
UpdateSidebarToggleGlyph();
UpdateTabStripFade();
// The column swap repositions the document pane; re-anchor the footer shadow once layout
// settles (TransformToVisual needs the final positions).
Dispatcher.BeginInvoke(System.Windows.Threading.DispatcherPriority.Loaded, (Action)UpdateFooterFade);
}
}
}