Mulit page view

src/Commands.h

@@ -28,6 +28,7 @@ Cmd* enum (e.g. CmdOpen) and a human-readable name (not used yet).
     V(CmdSinglePageView, "Single Page View")                              \
     V(CmdFacingView, "Facing View")                                       \
     V(CmdBookView, "Book View")                                           \
+    V(CmdMultiPage, "Multi Page View")                                \
     V(CmdToggleContinuousView, "Toggle Continuous View")                  \
     V(CmdToggleMangaMode, "Toggle Manga Mode")                            \
     V(CmdRotateLeft, "Rotate Left")                                       \

src/DisplayMode.cpp

@@ -19,6 +19,7 @@ bool IsContinuous(DisplayMode mode) {
         case DisplayMode::Continuous:
         case DisplayMode::ContinuousFacing:
         case DisplayMode::ContinuousBookView:
+        case DisplayMode::ContinuousMultiPage:
             return true;
     }
     return false;
@@ -32,6 +33,10 @@ bool IsBookView(DisplayMode mode) {
     return DisplayMode::BookView == mode || DisplayMode::ContinuousBookView == mode;
 }
 
+bool IsMultiPage(DisplayMode mode) {
+    return DisplayMode::MultiPage == mode || DisplayMode::ContinuousMultiPage == mode;
+}
+
 bool IsValidZoom(float zoom) {
     if ((kZoomMin - 0.01f <= zoom) && (zoom <= kZoomMax + 0.01f)) {
         return true;
@@ -56,7 +61,9 @@ static const char* displayModeNames =
     "book view\0"
     "continuous\0"
     "continuous facing\0"
-    "continuous book view\0";
+    "continuous book view\0"
+    "multi pages\0"
+    "continuous multi pages\0";
 
 const char* DisplayModeToString(DisplayMode mode) {
     int idx = (int)mode;

src/DisplayMode.h

@@ -5,6 +5,7 @@ bool IsSingle(DisplayMode mode);
 bool IsContinuous(DisplayMode mode);
 bool IsFacing(DisplayMode mode);
 bool IsBookView(DisplayMode mode);
+bool IsMultiPage(DisplayMode mode);
 bool IsValidZoom(float zoomLevel);
 
 const char* DisplayModeToString(DisplayMode mode);

src/DisplayModel.cpp

@@ -67,8 +67,12 @@
 // if true, we pre-render the pages right before and after the visible pages
 static bool gPredictiveRender = true;
 
-static int ColumnsFromDisplayMode(DisplayMode displayMode) {
+int DisplayModel::ColumnsFromDisplayMode(DisplayMode displayMode)  const {
     if (!IsSingle(displayMode)) {
+        if (IsMultiPage(displayMode)) {
+            SizeF pageSize = PageSizeAfterRotation(startPage);
+            return std::max(std::min((int)(viewPort.dx / (pageSize.dx * zoomReal)), 12),1);
+        }
         return 2;
     }
     return 1;
@@ -681,7 +685,9 @@ void DisplayModel::Relayout(float newZoomVirtual, int newRotation) {
        rotation, columns parameters. You can think of it as a simple
        table layout i.e. rows with a fixed number of columns. */
     int columns = ColumnsFromDisplayMode(GetDisplayMode());
-    int columnMaxWidth[2] = {0, 0};
+    int columnMaxWidth[12] = {
+        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
+    };
     int pageInARow = 0;
     int rowMaxPageDy = 0;
     for (int pageNo = 1; pageNo <= PageCount(); ++pageNo) {
@@ -766,8 +772,9 @@ void DisplayModel::Relayout(float newZoomVirtual, int newRotation) {
 
     // restart the layout if we detect we need to show scrollbars
     // (there are some edge cases we can't catch in the above loop)
-    int canvasDx = windowMargin.left + columnMaxWidth[0] + (columns == 2 ? pageSpacing.dx + columnMaxWidth[1] : 0) +
-                   windowMargin.right;
+    int canvasDx = windowMargin.left + columnMaxWidth[0] + windowMargin.right;
+    for (int c = 1; c < columns; c++)
+        canvasDx += pageSpacing.dx + columnMaxWidth[c];
     if ((!gGlobalPrefs->fixedPageUI.hideScrollbars) && (!needHScroll) && canvasDx > viewPort.dx) {
         needHScroll = true;
         viewPort.dy -= GetSystemMetrics(SM_CYHSCROLL);
@@ -1288,6 +1295,9 @@ void DisplayModel::SetDisplayMode(DisplayMode newDisplayMode, bool keepContinuou
             case DisplayMode::BookView:
                 newDisplayMode = DisplayMode::ContinuousBookView;
                 break;
+            case DisplayMode::MultiPage:
+                newDisplayMode = DisplayMode::ContinuousMultiPage;
+                break;
         }
     }
     if (displayMode == newDisplayMode) {

src/DisplayModel.h

@@ -71,6 +71,8 @@ struct DisplayModel : DocController {
 
     ~DisplayModel() override;
 
+    int ColumnsFromDisplayMode(DisplayMode displayMode) const;
+
     // meta data
     const char* GetFilePath() const override;
     const char* GetDefaultFileExt() const override;

src/Menu.cpp

@@ -86,7 +86,7 @@ bool gShowDebugMenu = false;
 
 // note: IDM_VIEW_SINGLE_PAGE - IDM_VIEW_CONTINUOUS and also
 //       CmdZoomFIT_PAGE - CmdZoomCUSTOM must be in a continuous range!
-static_assert(CmdViewLayoutLast - CmdViewLayoutFirst == 4, "view layout ids are not in a continuous range");
+static_assert(CmdViewLayoutLast - CmdViewLayoutFirst == 5, "view layout ids are not in a continuous range");
 static_assert(CmdZoomLast - CmdZoomFirst == 17, "zoom ids are not in a continuous range");
 
 // clang-format off
@@ -230,6 +230,10 @@ static MenuDef menuDefView[] = {
         _TRN("&Book View"),
         CmdBookView,
     },
+    {
+        _TRN("&Multi Page View"),
+        CmdMultiPage,
+    },
     {
         _TRN("Show &Pages Continuously"),
         CmdToggleContinuousView,
@@ -980,6 +984,7 @@ UINT_PTR removeIfChm[] = {
     CmdSinglePageView,
     CmdFacingView,
     CmdBookView,
+    CmdMultiPage,
     CmdToggleContinuousView,
     CmdRotateLeft,
     CmdRotateRight,
@@ -1550,6 +1555,8 @@ void MenuUpdateDisplayMode(MainWindow* win) {
         id = CmdFacingView;
     } else if (IsBookView(displayMode)) {
         id = CmdBookView;
+    } else if (IsMultiPage(displayMode)) {
+        id = CmdMultiPage;
     } else {
         CrashIf(win->ctrl || DisplayMode::Automatic != displayMode);
     }

src/Settings.h

@@ -15,6 +15,8 @@ enum class DisplayMode {
     Continuous,
     ContinuousFacing,
     ContinuousBookView,
+    MultiPage,
+    ContinuousMultiPage,
 };
 
 constexpr float kZoomFitPage = -1.f;

src/SumatraPDF.cpp

@@ -3638,6 +3638,10 @@ static void ToggleContinuousView(MainWindow* win) {
         case DisplayMode::ContinuousBookView:
             newMode = IsContinuous(newMode) ? DisplayMode::BookView : DisplayMode::ContinuousBookView;
             break;
+        case DisplayMode::MultiPage:
+        case DisplayMode::ContinuousMultiPage:
+            newMode = IsContinuous(newMode) ? DisplayMode::MultiPage : DisplayMode::ContinuousMultiPage;
+            break;
     }
     SwitchToDisplayMode(win, newMode);
 }
@@ -4970,6 +4974,10 @@ static LRESULT FrameOnCommand(MainWindow* win, HWND hwnd, UINT msg, WPARAM wp, L
             SwitchToDisplayMode(win, DisplayMode::BookView, true);
             break;
 
+        case CmdMultiPage:
+            SwitchToDisplayMode(win, DisplayMode::MultiPage, true);
+            break;
+
         case CmdToggleContinuousView:
             ToggleContinuousView(win);
             break;