Insert/remove vertical space on page. Implemented new pen "Insert Pen".

lib/components/canvas/_stroke.dart

@@ -277,6 +277,9 @@ class Stroke {
   double get maxY {
     return points.isEmpty ? 0 : points.map((point) => point.y).reduce(max);
   }
+  double get minY {
+    return points.isEmpty ? 0 : points.map((point) => point.y).reduce(min);
+  }
 
   RecognizedUnistroke? detectShape() {
     if (points.length < 3) return null;
@@ -360,6 +363,14 @@ class Stroke {
     }
   }
 
+  Offset get firstPoint {
+    return(Offset(points[0].x,points[0].y));
+  }
+
+  Offset get lastPoint {
+    return(Offset(points.last.x,points.last.y));
+  }
+
   Stroke copy() => Stroke(
         color: color,
         pressureEnabled: pressureEnabled,

lib/components/toolbar/pen_modal.dart

@@ -125,6 +125,26 @@ class _PenModalState extends State<PenModal> {
             tooltip: t.editor.pens.shapePen,
             icon: const FaIcon(ShapePen.shapePenIcon),
           ),
+          const SizedBox.square(dimension: 8),
+          IconButton(
+            onPressed: () => setState(() {
+              widget.setTool(Pen.insertPen());
+            }),
+            style: TextButton.styleFrom(
+              foregroundColor: Pen.currentPen.icon == Pen.insertPenIcon
+                  ? Theme.of(context).colorScheme.secondary
+                  : Theme.of(context).colorScheme.onSurface,
+              backgroundColor: Pen.currentPen.icon == Pen.insertPenIcon
+                  ? Theme.of(context)
+                  .colorScheme
+                  .secondary
+                  .withValues(alpha: 0.1)
+                  : Colors.transparent,
+              shape: const CircleBorder(),
+            ),
+            tooltip: t.editor.pens.insertPen,
+            icon: const FaIcon(Pen.insertPenIcon),
+          ),
         ],
       ],
     );

lib/data/editor/page.dart

@@ -25,7 +25,7 @@ class EditorPage extends Listenable implements HasSize {
   static const Size defaultSize = Size(defaultWidth, defaultHeight);
 
   @override
-  final Size size;
+  Size size;
 
   late final CanvasKey innerCanvasKey = CanvasKey();
   RenderBox? _renderBox;

lib/data/tools/_tool.dart

@@ -24,6 +24,7 @@ class _TextEditingTool extends Tool {
 enum ToolId {
   fountainPen('fountainPen'),
   ballpointPen('ballpointPen'),
+  insertPen('insertPen'),
   highlighter('Highlighter'),
   pencil('Pencil'),
   shapePen('ShapePen'),

lib/data/tools/pen.dart

@@ -46,6 +46,18 @@ class Pen extends Tool {
         color = Color(stows.lastBallpointPenColor.value),
         toolId = ToolId.ballpointPen;
 
+  Pen.insertPen()
+      : name = t.editor.pens.insertPen,
+        sizeMin = 1,
+        sizeMax = 25,
+        sizeStep = 1,
+        icon = insertPenIcon,
+        options = Prefs.lastBallpointPenOptions.value,
+        pressureEnabled = false,
+        color = Color(Prefs.lastBallpointPenColor.value),
+        toolId = ToolId.insertPen;
+
+
   final String name;
   final double sizeMin, sizeMax, sizeStep;
   late final int sizeStepsBetweenMinAndMax =
@@ -57,6 +69,7 @@ class Pen extends Tool {
 
   static const IconData fountainPenIcon = FontAwesomeIcons.penFancy;
   static const IconData ballpointPenIcon = FontAwesomeIcons.pen;
+  static const IconData insertPenIcon = FontAwesomeIcons.arrowsUpDown;
 
   static Stroke? currentStroke;
   Color color;

lib/i18n/strings_en.g.dart

@@ -624,6 +624,7 @@ class TranslationsEditorPensEn {
 	// Translations
 	String get fountainPen => 'Fountain pen';
 	String get ballpointPen => 'Ballpoint pen';
+	String get insertPen => 'Insert space pen';
 	String get highlighter => 'Highlighter';
 	String get pencil => 'Pencil';
 	String get shapePen => 'Shape pen';

lib/pages/editor/editor.dart

@@ -136,6 +136,11 @@ class EditorState extends State<Editor> {
           Pen.currentPen = Pen.ballpointPen();
         }
         return Pen.currentPen;
+      case ToolId.insertPen:
+        if (Pen.currentPen.toolId != Prefs.lastTool.value) {
+          Pen.currentPen = Pen.insertPen();
+        }
+        return Pen.currentPen;
       case ToolId.shapePen:
         if (Pen.currentPen.toolId != stows.lastTool.value) {
           Pen.currentPen = ShapePen();
@@ -628,6 +633,7 @@ class EditorState extends State<Editor> {
     moveOffset += offset;
   }
 
+
   void onDrawEnd(ScaleEndDetails details) {
     final page = coreInfo.pages[dragPageIndex!];
     bool shouldSave = true;
@@ -643,14 +649,23 @@ class EditorState extends State<Editor> {
           newStroke.convertToLine();
         }
 
-        createPage(newStroke.pageIndex);
-        page.insertStroke(newStroke);
-        history.recordChange(EditorHistoryItem(
-          type: EditorHistoryItemType.draw,
-          pageIndex: dragPageIndex!,
-          strokes: [newStroke],
-          images: [],
-        ));
+        if (currentTool.toolId != ToolId.insertPen) {
+          // normal pen
+          createPage(newStroke.pageIndex);
+          page.insertStroke(newStroke);
+          history.recordChange(EditorHistoryItem(
+            type: EditorHistoryItemType.draw,
+            pageIndex: dragPageIndex!,
+            strokes: [newStroke],
+            images: [],
+          ));
+        }
+        else {
+          // is insert pen, I must insert free space of the vertical length of stroke
+          double yFirst=newStroke.firstPoint.dy;
+          double yLast=newStroke.lastPoint.dy;
+          moveItemsOnPageUpDown(page,dragPageIndex!,yFirst,yLast); // move all items below up/down
+        }
       } else if (currentTool is Eraser) {
         final erased = (currentTool as Eraser).onDragEnd();
         if (tmpTool != null &&
@@ -706,6 +721,82 @@ class EditorState extends State<Editor> {
     if (shouldSave) autosaveAfterDelay();
   }
 
+  // move all items below maxY down by maxY-minY
+  void moveItemsOnPageUpDown(EditorPage page,int pageIndex, double yFirst,double yLast){
+    if ((yFirst-yLast).abs()<1.0){
+      return;  // too small move
+    }
+
+    final double maxY;
+    maxY=yFirst; // all items below first point
+    List<Stroke> strokesBelow=[];
+    double maxStrokesY;
+    maxStrokesY=0.0;
+    for (int i = 0; i < page.strokes.length; i++) {
+      final stroke = page.strokes[i];
+      if (stroke.minY>=maxY) {
+        // stroke is below inserted place
+        strokesBelow.add(stroke); // add stroke to list of interest
+        if (stroke.maxY>maxStrokesY) {
+          maxStrokesY=stroke.maxY;   // the lowest possible point of strokes
+        }
+      }
+    }
+
+    List<EditorImage> imagesBelow=[];
+
+    for (int i = 0; i < page.images.length; i++) {
+      final EditorImage image = page.images[i];
+      if (image.dstRect.top>=maxY){
+        //image is below inserted place
+        imagesBelow.add(image); // add stroke to list of interest
+        if (image.dstRect.bottom>maxStrokesY) {
+          maxStrokesY=image.dstRect.bottom;   // the lowest possible point of images
+        }
+      }
+    }
+    if (strokesBelow.length==0 && imagesBelow.length==0) {
+      return;  // nothing to move
+    }
+    final double shiftY=yLast-yFirst;
+    if (maxStrokesY+shiftY>page.size.height){
+      // must enlarge page
+      page.size=Size(page.size.width,maxStrokesY+shiftY);
+    }
+    if (maxStrokesY+shiftY<EditorPage.defaultHeight){
+      // page will be smaller than default height set it to default height
+      page.size=Size(page.size.width,EditorPage.defaultHeight);
+    }
+    // and now move items
+    setState(() {
+      Offset moveOffset = Offset(0.0, shiftY);
+      for (Stroke stroke in strokesBelow) {
+        stroke.shift(moveOffset);
+      }
+      for (EditorImage image in imagesBelow) {
+        image.dstRect = Rect.fromLTRB(
+          image.dstRect.left,
+          image.dstRect.top+moveOffset.dy,
+          image.dstRect.right,
+          image.dstRect.bottom+moveOffset.dy,
+        );
+      }
+    });
+
+    history.recordChange(EditorHistoryItem(
+      type: EditorHistoryItemType.move,
+      pageIndex: pageIndex,
+      strokes: strokesBelow,
+      images: imagesBelow,
+      offset: Rect.fromLTRB(
+        moveOffset.dx,
+        moveOffset.dy,
+        moveOffset.dx,
+        moveOffset.dy,
+      ),
+    ));
+  }
+
   void onInteractionEnd(ScaleEndDetails details) {
     // reset after 1ms to keep track of the same gesture only
     _lastSeenPointerCountTimer?.cancel();