Add CmdExpandToCurrentPage to expand TOC to current page (fixes #1998)

kjk · claude · kjk · commit 4831e1f8d407 · 2026-06-17T16:37:25.000+02:00
New command that expands the Bookmarks (table of contents) tree down to the
entry matching the current page and selects/scrolls to it, like Explorer's
"Expand to current folder". Available from the TOC sidebar right-click menu
and the Ctrl+K command palette.

Implemented as ExpandTocToCurrentPage() in TableOfContents.cpp: finds the
best-matching TocItem for the current page (TreeItemForPageNo), then uses
TreeView_EnsureVisible to expand collapsed ancestors and scroll into view,
and selects the item.

Includes a GUI test (tests/issue-1998.ts) that drives the app via WM_COMMAND
and reads the TOC tree state with cross-process TreeView messages: collapses
the tree, invokes the command, and asserts the tree expands to the current
page with an item selected.

Co-Authored-By: Claude Opus 4.8 (1M context) &lt;noreply@anthropic.com&gt;
diff --git a/cmd/gen-commands.ts b/cmd/gen-commands.ts
@@ -236,6 +236,7 @@ export const commands = [
     "CmdCommandPaletteTOC", "Command Palette: Table Of Contents",
     "CmdDebugToggleRenderInfo", "Debug: Toggle Render Queue Info",
     "CmdConvertImageToPdf", "Convert Image To PDF",
+    "CmdExpandToCurrentPage", "Expand TOC to Current Page",
     "CmdNone", "Do nothing",
 ];
 
diff --git a/docs/md/Commands.md b/docs/md/Commands.md
@@ -39,6 +39,7 @@ CmdToggleBookmarks,F12,Toggle Bookmarks,
 CmdToggleTableOfContents,,Toggle Table Of Contents,ver 3.6+
 CmdCollapseAll,,Collapse All,
 CmdExpandAll,,Expand All,
+CmdExpandToCurrentPage,,Expand TOC to Current Page,"In the Bookmarks (table of contents) sidebar, expand the tree down to the entry for the current page and select it, ver 3.7+"
 CmdOpenEmbeddedPDF,,Open Embedded PDF,
 CmdSaveEmbeddedFile,,Save Embedded File...,
 CmdCreateShortcutToFile,,Create .lnk Shortcut,
diff --git a/docs/md/Version-history.md b/docs/md/Version-history.md
@@ -4,6 +4,7 @@
 
 Available in [pre-release](https://www.sumatrapdfreader.org/prerelease) builds.
 
+- add `CmdExpandToCurrentPage` (`Expand TOC to Current Page`, in the Bookmarks sidebar right-click menu and the `Ctrl + k` command palette) to expand the table of contents tree down to the current page's entry and select it, like Explorer's "Expand to current folder" (fixes #1998)
 - Save As now warns instead of failing silently when a file can't be written (e.g. the destination path exceeds the Windows `MAX_PATH` limit); previously there was no way to tell the save hadn't happened (fixes #1016)
 - can convert an image to a PDF: right-click an image (or an open image document) and choose `Image / Convert to PDF`, or pick `PDF` in the format drop-down of the Save Image dialog. The new PDF gets `CreationDate`/`ModDate` metadata with the current time and time zone (fixes #949)
 - in the Favorites pane and menu, a favorite for a file with a long name now shows your favorite's name first, then the file name, so the name you gave it is no longer pushed out of view (fixes #829, #2236)
diff --git a/src/Commands.cpp b/src/Commands.cpp
@@ -246,6 +246,7 @@ static SeqStrings gCommandNames =
     "CmdCommandPaletteTOC\0"
     "CmdDebugToggleRenderInfo\0"
     "CmdConvertImageToPdf\0"
+    "CmdExpandToCurrentPage\0"
     "CmdNone\0"
     "\0";
 
@@ -482,6 +483,7 @@ static i32 gCommandIds[] = {
     CmdCommandPaletteTOC,
     CmdDebugToggleRenderInfo,
     CmdConvertImageToPdf,
+    CmdExpandToCurrentPage,
     CmdNone,
 };
 
@@ -718,6 +720,7 @@ SeqStrings gCommandDescriptions =
     "Command Palette: Table Of Contents\0"
     "Debug: Toggle Render Queue Info\0"
     "Convert Image To PDF\0"
+    "Expand TOC to Current Page\0"
     "Do nothing\0"
     "\0";
 // clang-format on
diff --git a/src/Commands.h b/src/Commands.h
@@ -241,7 +241,8 @@ enum {
     CmdCommandPaletteTOC = 430,
     CmdDebugToggleRenderInfo = 431,
     CmdConvertImageToPdf = 432,
-    CmdNone = 433,
+    CmdExpandToCurrentPage = 433,
+    CmdNone = 434,
 
     /* range for file history */
     CmdFileHistoryFirst,
diff --git a/src/SumatraPDF.cpp b/src/SumatraPDF.cpp
@@ -7042,6 +7042,10 @@ static LRESULT FrameOnCommand(MainWindow* win, HWND hwnd, UINT msg, WPARAM wp, L
             }
             break;
 
+        case CmdExpandToCurrentPage:
+            ExpandTocToCurrentPage(win);
+            break;
+
         case CmdScrollUpHalfPage: {
             if (win->IsCurrentTabAbout()) {
                 HomePageOnVScroll(win, SB_PAGEUP);
diff --git a/src/TableOfContents.cpp b/src/TableOfContents.cpp
@@ -367,6 +367,37 @@ void UpdateTocSelection(MainWindow* win, int currPageNo) {
     treeView->SelectItem(toSelect);
 }
 
+// expand the table of contents tree down to the entry matching the current
+// page, then select and scroll to it (issue #1998, like Explorer's
+// "Expand to current folder")
+void ExpandTocToCurrentPage(MainWindow* win) {
+    if (!win || !win->IsDocLoaded()) {
+        return;
+    }
+    // make sure the bookmarks (table of contents) sidebar is visible
+    if (!win->tocVisible) {
+        SetSidebarVisibility(win, true, gGlobalPrefs->showFavorites);
+    }
+    if (!win->tocLoaded || !win->tocVisible) {
+        return;
+    }
+    TreeView* treeView = win->tocTreeView;
+    int currPageNo = win->ctrl->CurrentPageNo();
+    TocItem* item = TreeItemForPageNo(treeView, currPageNo);
+    if (!item) {
+        return;
+    }
+    HTREEITEM hi = treeView->GetHandleByTreeItem((TreeItem)item);
+    if (!hi) {
+        return;
+    }
+    // TreeView_EnsureVisible expands any collapsed ancestors and scrolls the
+    // item into view, which is exactly the "expand to current page" behavior
+    TreeView_EnsureVisible(treeView->hwnd, hi);
+    treeView->SelectItem((TreeItem)item);
+    HwndSetFocus(treeView->hwnd);
+}
+
 static void UpdateDocTocExpansionStateRecur(TreeView* treeView, Vec<int>& tocState, TocItem* tocItem) {
     while (tocItem) {
         // items without children cannot be toggled
@@ -538,6 +569,10 @@ static MenuDef menuDefContextToc[] = {
         _TRN("Collapse All"),
         CmdCollapseAll,
     },
+    {
+        _TRN("Expand to Current Page"),
+        CmdExpandToCurrentPage,
+    },
     {
         kMenuSeparator,
         0,
@@ -673,6 +708,9 @@ static void TocContextMenu(ContextMenuEvent* ev) {
         case CmdCollapseAll:
             win->tocTreeView->CollapseAll();
             break;
+        case CmdExpandToCurrentPage:
+            ExpandTocToCurrentPage(win);
+            break;
         case CmdFavoriteAdd:
             AddFavoriteFromToc(win, dti);
             break;
diff --git a/src/TableOfContents.h b/src/TableOfContents.h
@@ -6,6 +6,7 @@ void ClearTocBox(MainWindow*);
 void ToggleTocBox(MainWindow*);
 void LoadTocTree(MainWindow*);
 void UpdateTocSelection(MainWindow*, int currPageNo);
+void ExpandTocToCurrentPage(MainWindow*);
 void UpdateTocExpansionState(Vec<int>& tocState, TreeView*, TocTree*);
 void UnsubclassToc(MainWindow*);
 void TocFilterChanged(MainWindow*);
diff --git a/tests/all.ts b/tests/all.ts
@@ -10,6 +10,7 @@
 // and register it in the `tests` array below.
 
 import { buildApp } from "./util.ts";
+import { testit as issue1998 } from "./issue-1998.ts";
 import { testit as issue906 } from "./issue-906.ts";
 import { testit as issue933 } from "./issue-933.ts";
 import { testit as issue4967 } from "./issue-4967.ts";
@@ -24,6 +25,7 @@ import { testit as issue5681 } from "./issue-5681.ts";
 import { testit as issueChmLzx } from "./issue-chm-lzx.ts";
 
 const tests: [string, () => void | Promise<void>][] = [
+  ["issue-1998", issue1998],
   ["issue-906", issue906],
   ["issue-933", issue933],
   ["issue-4967", issue4967],
diff --git a/tests/issue-1998.ts b/tests/issue-1998.ts
@@ -0,0 +1,88 @@
+// Test for issue #1998: "Expand to current page in toc tree".
+//
+// CmdExpandToCurrentPage expands the table-of-contents tree down to the entry
+// matching the current page and selects it (like Explorer's "Expand to current
+// folder"). Implemented in src/TableOfContents.cpp (ExpandTocToCurrentPage),
+// wired to the TOC context menu and the global command dispatcher.
+//
+// The test opens a PDF with a nested TOC, navigates to the last page, collapses
+// the whole tree, then invokes the command via WM_COMMAND and reads the tree
+// state with cross-process TreeView messages. After the command, the path to the
+// (deeply nested) last-page entry must be expanded -- so more tree rows are
+// visible than when fully collapsed -- and an item must be selected. Reverting
+// the fix leaves the tree collapsed with no expansion, so the test fails.
+//
+// Needs a PDF with a multi-level outline; uses one from the local bugs folder
+// and skips cleanly if it isn't present (so tests/all.ts keeps going).
+
+import { spawnSync } from "node:child_process";
+import { copyFileSync, existsSync, mkdirSync, rmSync, writeFileSync } from "node:fs";
+import { join } from "node:path";
+import { EXE, ROOT, tmpPath } from "./util";
+
+// a PDF with a nested (multi-level) table of contents
+const TOC_PDF = "C:\\Users\\kjk\\OneDrive\\!sumatra\\bugs\\bug-1352-merged_manuals-1.4.2.pdf";
+
+const SETTINGS = [
+  `ShowToc = true`,
+  `ShowFavorites = false`,
+  `DefaultDisplayMode = continuous`,
+  `DefaultZoom = fit page`,
+  `Scrollbars = windows`,
+  `RestoreSession = false`,
+  `ShowStartPage = false`,
+  `CheckForUpdates = false`,
+  ``,
+].join("\n");
+
+export async function testit(): Promise<void> {
+  if (!existsSync(TOC_PDF)) {
+    console.log(`  SKIP: TOC test PDF not found: ${TOC_PDF}`);
+    return;
+  }
+
+  // copy the PDF out of OneDrive to a local path -- opening a cloud-backed file
+  // can block/delay window creation (hydration), which breaks the automation
+  const pdf = tmpPath("issue-1998.pdf");
+  copyFileSync(TOC_PDF, pdf);
+
+  const appdata = tmpPath("issue-1998-appdata");
+  rmSync(appdata, { recursive: true, force: true });
+  mkdirSync(appdata, { recursive: true });
+  writeFileSync(join(appdata, "SumatraPDF-settings.txt"), SETTINGS);
+
+  const ps1 = join(ROOT, "tests", "issue-1998.verify.ps1");
+  const r = spawnSync(
+    "powershell.exe",
+    ["-NoProfile", "-ExecutionPolicy", "Bypass", "-File", ps1, "-Exe", EXE, "-Pdf", pdf, "-AppData", appdata],
+    { encoding: "utf8", timeout: 90_000 },
+  );
+  const out = (r.stdout || "") + (r.stderr || "");
+  const m = out.match(/RESULT collapsed=(\d+) after=(\d+) hasSelection=(\d+)/);
+  if (!m) {
+    throw new Error(`could not read TOC tree state; output:\n${out}`);
+  }
+  const collapsed = parseInt(m[1], 10);
+  const after = parseInt(m[2], 10);
+  const hasSelection = m[3] === "1";
+  console.log(`  collapsed rows=${collapsed}, after-expand rows=${after}, hasSelection=${hasSelection}`);
+
+  if (collapsed <= 0) {
+    throw new Error(`baseline collapsed tree has no rows (${collapsed}) -- test setup wrong`);
+  }
+  if (!hasSelection) {
+    throw new Error(`CmdExpandToCurrentPage did not select a TOC entry`);
+  }
+  if (after <= collapsed) {
+    throw new Error(
+      `CmdExpandToCurrentPage did not expand the tree to the current page ` +
+        `(visible rows ${collapsed} -> ${after}; expected an increase)`,
+    );
+  }
+  console.log(`  expanded TOC to current page: ${collapsed} -> ${after} visible rows ✓`);
+}
+
+if (import.meta.main) {
+  const { runStandalone } = await import("./util");
+  await runStandalone(testit);
+}
diff --git a/tests/issue-1998.verify.ps1 b/tests/issue-1998.verify.ps1
@@ -0,0 +1,123 @@
+# Helper for tests/issue-1998.ts. Verifies CmdExpandToCurrentPage:
+# opens a PDF with a nested table of contents, goes to the last page, collapses
+# the TOC tree, invokes the command, and reports how many tree rows are visible
+# before vs. after plus whether an item ends up selected.
+#
+# Driving by injected input doesn't work on this machine, but WM_COMMAND (to
+# trigger commands) and cross-process TreeView messages (to read state) do work
+# (see project memory env-gui-automation).
+param([string]$Exe, [string]$Pdf, [string]$AppData)
+$ErrorActionPreference = "Stop"
+
+Add-Type @"
+using System;
+using System.Text;
+using System.Runtime.InteropServices;
+public class W {
+  public delegate bool EnumProc(IntPtr h, IntPtr l);
+  [DllImport("user32.dll")] public static extern bool EnumWindows(EnumProc cb, IntPtr l);
+  [DllImport("user32.dll")] public static extern bool EnumChildWindows(IntPtr p, EnumProc cb, IntPtr l);
+  [DllImport("user32.dll", CharSet=CharSet.Unicode)] public static extern int GetClassNameW(IntPtr h, StringBuilder s, int n);
+  [DllImport("user32.dll")] public static extern uint GetWindowThreadProcessId(IntPtr h, out uint pid);
+  [DllImport("user32.dll")] public static extern IntPtr SendMessageW(IntPtr h, uint msg, IntPtr w, IntPtr l);
+  [DllImport("user32.dll")] public static extern bool PostMessageW(IntPtr h, uint msg, IntPtr w, IntPtr l);
+}
+"@
+
+function Cls([IntPtr]$h) { $sb = New-Object Text.StringBuilder 256; [W]::GetClassNameW($h, $sb, 256) | Out-Null; $sb.ToString() }
+
+# TreeView messages
+$TVM_GETNEXTITEM = 0x110A
+$TVM_EXPAND      = 0x1102
+$TVGN_ROOT       = 0x0
+$TVGN_NEXT       = 0x1
+$TVGN_CARET      = 0x9
+$TVGN_NEXTVISIBLE= 0x6
+$TVE_COLLAPSE    = 0x1
+$WM_COMMAND      = 0x111
+
+function TvNext([IntPtr]$tree, [int]$flag, [IntPtr]$item) {
+  return [W]::SendMessageW($tree, $TVM_GETNEXTITEM, [IntPtr]$flag, $item)
+}
+function CountVisible([IntPtr]$tree) {
+  $n = 0
+  $it = TvNext $tree $TVGN_ROOT ([IntPtr]::Zero)
+  while ($it -ne [IntPtr]::Zero) {
+    $n++
+    $it = TvNext $tree $TVGN_NEXTVISIBLE $it
+    if ($n -gt 100000) { break }
+  }
+  return $n
+}
+function CollapseRoots([IntPtr]$tree) {
+  $it = TvNext $tree $TVGN_ROOT ([IntPtr]::Zero)
+  while ($it -ne [IntPtr]::Zero) {
+    [W]::SendMessageW($tree, $TVM_EXPAND, [IntPtr]$TVE_COLLAPSE, $it) | Out-Null
+    $it = TvNext $tree $TVGN_NEXT $it
+  }
+}
+
+# kill any stale dev-build instances so reuse-instance can't forward our launch
+# to an old window (which would leave our process window-less)
+Get-Process SumatraPDF-dll -ErrorAction SilentlyContinue | ForEach-Object { try { $_.Kill() } catch {} }
+Start-Sleep -Milliseconds 300
+
+$proc = Start-Process -FilePath $Exe -ArgumentList @("-for-testing", "-appdata", $AppData, $Pdf) -PassThru
+$wantPid = [uint32]$proc.Id
+
+# note: the EnumWindows/EnumChildWindows callbacks must NOT call PowerShell
+# functions (calling back into the runspace from a native callback misbehaves) --
+# inline the class-name lookup instead.
+function FindFrame {
+  $script:frame = [IntPtr]::Zero
+  $cb = [W+EnumProc] { param($h, $l)
+    $p = [uint32]0; [W]::GetWindowThreadProcessId($h, [ref]$p) | Out-Null
+    if ($p -eq $wantPid) {
+      $sb = New-Object Text.StringBuilder 256; [W]::GetClassNameW($h, $sb, 256) | Out-Null
+      if ($sb.ToString() -eq "SUMATRA_PDF_FRAME") { $script:frame = $h; return $false }
+    }
+    return $true }
+  [W]::EnumWindows($cb, [IntPtr]::Zero) | Out-Null
+  return $script:frame
+}
+function FindTree([IntPtr]$frame) {
+  $script:tree = [IntPtr]::Zero
+  $cb = [W+EnumProc] { param($h, $l)
+    $sb = New-Object Text.StringBuilder 256; [W]::GetClassNameW($h, $sb, 256) | Out-Null
+    if ($sb.ToString() -eq "SysTreeView32") { $script:tree = $h; return $false }
+    return $true }
+  [W]::EnumChildWindows($frame, $cb, [IntPtr]::Zero) | Out-Null
+  return $script:tree
+}
+
+$frame = [IntPtr]::Zero
+for ($i = 0; $i -lt 60; $i++) { $frame = FindFrame; if ($frame -ne [IntPtr]::Zero) { break }; Start-Sleep -Milliseconds 200 }
+if ($frame -eq [IntPtr]::Zero) { Write-Output "ERROR no-frame"; $proc.Kill(); exit 1 }
+
+# wait for the TOC tree to load with items
+$tree = [IntPtr]::Zero
+for ($i = 0; $i -lt 60; $i++) {
+  $tree = FindTree $frame
+  if ($tree -ne [IntPtr]::Zero -and (CountVisible $tree) -gt 0) { break }
+  Start-Sleep -Milliseconds 250
+}
+if ($tree -eq [IntPtr]::Zero) { Write-Output "ERROR no-tree"; $proc.Kill(); exit 1 }
+
+# go to the last page (deep in the document, under nested TOC entries)
+[W]::SendMessageW($frame, $WM_COMMAND, [IntPtr]264, [IntPtr]::Zero) | Out-Null   # CmdGoToLastPage
+Start-Sleep -Milliseconds 600
+
+# collapse the whole tree, then measure
+CollapseRoots $tree
+Start-Sleep -Milliseconds 300
+$collapsed = CountVisible $tree
+
+# invoke the command under test
+[W]::SendMessageW($frame, $WM_COMMAND, [IntPtr]433, [IntPtr]::Zero) | Out-Null   # CmdExpandToCurrentPage
+Start-Sleep -Milliseconds 600
+$after = CountVisible $tree
+$caret = TvNext $tree $TVGN_CARET ([IntPtr]::Zero)
+$hasSel = if ($caret -ne [IntPtr]::Zero) { 1 } else { 0 }
+
+Write-Output ("RESULT collapsed={0} after={1} hasSelection={2}" -f $collapsed, $after, $hasSel)
+try { $proc.Kill() } catch {}
