KeepTogether disable for not fit in keepTogether tree fix

DEVSIX-3468

Autoported commit.
Original commit hash: [91bea8fa7]

Author: BezrukovM

itext.tests/itext.layout.tests/itext/layout/KeepTogetherTest.cs

@@ -780,9 +780,9 @@ public virtual void SmallFloatInsideKeptTogetherTableTest02() {
         }
 
         [NUnit.Framework.Test]
-        [LogMessage(iText.IO.LogMessageConstant.ELEMENT_DOES_NOT_FIT_AREA, Count = 2)]
-        public virtual void ContentOverlappingInDivWithKeepTogetherTest() {
-            String filename = "contentOverlappingInDivWithKeepTogether.pdf";
+        [LogMessage(iText.IO.LogMessageConstant.ELEMENT_DOES_NOT_FIT_AREA)]
+        public virtual void KeepTogetherTreeWithParentNotFitOnDocumentTest() {
+            String filename = "keepTogetherTreeWithParentNotFitOnDocument.pdf";
             String outFile = destinationFolder + filename;
             String cmpFileName = sourceFolder + "cmp_" + filename;
             using (Document doc = new Document(new PdfDocument(new PdfWriter(outFile)))) {
@@ -803,9 +803,9 @@ public virtual void ContentOverlappingInDivWithKeepTogetherTest() {
         }
 
         [NUnit.Framework.Test]
-        [LogMessage(iText.IO.LogMessageConstant.ELEMENT_DOES_NOT_FIT_AREA, Count = 2)]
-        public virtual void MissContentAndOverlappingInDivNoKeepTogetherTest() {
-            String filename = "missContentAndOverlappingInDivNoKeepTogether.pdf";
+        [LogMessage(iText.IO.LogMessageConstant.ELEMENT_DOES_NOT_FIT_AREA)]
+        public virtual void KeepTogetherSubTreeWithParentNotFitOnDocumentTest() {
+            String filename = "keepTogetherSubTreeWithParentNotFitOnDocument.pdf";
             String outFile = destinationFolder + filename;
             String cmpFileName = sourceFolder + "cmp_" + filename;
             using (Document doc = new Document(new PdfDocument(new PdfWriter(outFile)))) {
@@ -827,9 +827,33 @@ public virtual void MissContentAndOverlappingInDivNoKeepTogetherTest() {
         }
 
         [NUnit.Framework.Test]
-        [LogMessage(iText.IO.LogMessageConstant.ELEMENT_DOES_NOT_FIT_AREA, Count = 2)]
-        public virtual void ContentOverlappingDivKeepTogetherInRectTest() {
-            String filename = "contentOverlappingDivKeepTogetherInRect.pdf";
+        [LogMessage(iText.IO.LogMessageConstant.ELEMENT_DOES_NOT_FIT_AREA)]
+        public virtual void KeepTogetherSubTreeWithChildKeepTogetherFalseAndParentNotFitOnDocumentTest() {
+            String filename = "keepTogetherSubTreeWithChildKeepTogetherFalseAndParentNotFitOnDocument.pdf";
+            String outFile = destinationFolder + filename;
+            String cmpFileName = sourceFolder + "cmp_" + filename;
+            using (Document doc = new Document(new PdfDocument(new PdfWriter(outFile)))) {
+                doc.GetPdfDocument().AddNewPage(PageSize.A5.Rotate());
+                Div main = new Div();
+                Div child1 = CreateChildDivWithText(main, null).SetKeepTogether(true);
+                CreateChildDivWithText(child1, BIG_TEXT);
+                Div div1_2 = CreateChildDivWithText(child1, null).SetKeepTogether(false);
+                CreateChildDivWithText(div1_2, "Section A");
+                CreateChildDivWithText(div1_2, null).Add(new Paragraph(MEDIUM_TEXT).SetFirstLineIndent(20));
+                // KEEP_TOGETHER is not set here
+                Div child2 = CreateChildDivWithText(main, null);
+                CreateChildDivWithText(child2, "Section B");
+                CreateChildDivWithText(child2, null);
+                CreateChildDivWithText(child2, "Lorem ipsum dolor sit amet!");
+                doc.Add(main);
+            }
+            NUnit.Framework.Assert.IsNull(new CompareTool().CompareByContent(outFile, cmpFileName, destinationFolder));
+        }
+
+        [NUnit.Framework.Test]
+        [LogMessage(iText.IO.LogMessageConstant.ELEMENT_DOES_NOT_FIT_AREA)]
+        public virtual void KeepTogetherTreeWithParentNotFitOnPageCanvasTest() {
+            String filename = "keepTogetherTreeWithParentNotFitOnPageCanvas.pdf";
             String outFile = destinationFolder + filename;
             String cmpFileName = sourceFolder + "cmp_" + filename;
             using (PdfDocument pdfDoc = new PdfDocument(new PdfWriter(outFile))) {

itext.tests/itext.layout.tests/resources/itext/layout/KeepTogetherTest/cmp_contentOverlappingDivKeepTogetherInRect.pdf

@@ -163,53 +163,19 @@ public override void AddChild(IRenderer renderer) {
                             }
                             else {
                                 if (currentArea.IsEmptyArea() && result.GetAreaBreak() == null) {
-                                    if (true.Equals(result.GetOverflowRenderer().GetModelElement().GetProperty<bool?>(Property.KEEP_TOGETHER))
-                                        ) {
-                                        result.GetOverflowRenderer().GetModelElement().SetProperty(Property.KEEP_TOGETHER, false);
-                                        ILog logger = LogManager.GetLogger(typeof(RootRenderer));
-                                        logger.Warn(MessageFormatUtil.Format(iText.IO.LogMessageConstant.ELEMENT_DOES_NOT_FIT_AREA, "KeepTogether property will be ignored."
-                                            ));
-                                        if (!rendererIsFloat) {
-                                            rootRendererStateHandler.AttemptGoBackToStoredPreviousStateAndStoreNextState(this);
-                                        }
+                                    bool keepTogetherChanged = TryDisableKeepTogether(result, rendererIsFloat, rootRendererStateHandler);
+                                    bool areKeepTogetherAndForcedPlacementBothNotChanged = !keepTogetherChanged;
+                                    if (areKeepTogetherAndForcedPlacementBothNotChanged) {
+                                        areKeepTogetherAndForcedPlacementBothNotChanged = !UpdateForcedPlacement(renderer, result.GetOverflowRenderer
+                                            ());
                                     }
-                                    else {
-                                        if (null != result.GetCauseOfNothing() && true.Equals(result.GetCauseOfNothing().GetProperty<bool?>(Property
-                                            .KEEP_TOGETHER))) {
-                                            // set KEEP_TOGETHER false on the deepest parent (maybe the element itself) to have KEEP_TOGETHER == true
-                                            IRenderer theDeepestKeptTogether = result.GetCauseOfNothing();
-                                            IRenderer parent;
-                                            while (null == theDeepestKeptTogether.GetModelElement() || null == theDeepestKeptTogether.GetModelElement(
-                                                ).GetOwnProperty<bool?>(Property.KEEP_TOGETHER)) {
-                                                parent = ((AbstractRenderer)theDeepestKeptTogether).parent;
-                                                if (parent == null) {
-                                                    break;
-                                                }
-                                                theDeepestKeptTogether = parent;
-                                            }
-                                            theDeepestKeptTogether.GetModelElement().SetProperty(Property.KEEP_TOGETHER, false);
-                                            ILog logger = LogManager.GetLogger(typeof(RootRenderer));
-                                            logger.Warn(MessageFormatUtil.Format(iText.IO.LogMessageConstant.ELEMENT_DOES_NOT_FIT_AREA, "KeepTogether property of inner element will be ignored."
-                                                ));
-                                            if (!rendererIsFloat) {
-                                                rootRendererStateHandler.AttemptGoBackToStoredPreviousStateAndStoreNextState(this);
-                                            }
-                                        }
-                                        else {
-                                            if (!true.Equals(renderer.GetProperty<bool?>(Property.FORCED_PLACEMENT))) {
-                                                result.GetOverflowRenderer().SetProperty(Property.FORCED_PLACEMENT, true);
-                                                ILog logger = LogManager.GetLogger(typeof(RootRenderer));
-                                                logger.Warn(MessageFormatUtil.Format(iText.IO.LogMessageConstant.ELEMENT_DOES_NOT_FIT_AREA, ""));
-                                            }
-                                            else {
-                                                // FORCED_PLACEMENT was already set to the renderer and
-                                                // LogMessageConstant.ELEMENT_DOES_NOT_FIT_AREA message was logged.
-                                                // This else-clause should never be hit, otherwise there is a bug in FORCED_PLACEMENT implementation.
-                                                System.Diagnostics.Debug.Assert(false);
-                                                // Still handling this case in order to avoid nasty infinite loops.
-                                                break;
-                                            }
-                                        }
+                                    if (areKeepTogetherAndForcedPlacementBothNotChanged) {
+                                        // FORCED_PLACEMENT was already set to the renderer and
+                                        // LogMessageConstant.ELEMENT_DOES_NOT_FIT_AREA message was logged.
+                                        // This else-clause should never be hit, otherwise there is a bug in FORCED_PLACEMENT implementation.
+                                        System.Diagnostics.Debug.Assert(false);
+                                        // Still handling this case in order to avoid nasty infinite loops.
+                                        break;
                                     }
                                 }
                                 else {
@@ -520,5 +486,49 @@ private void AddWaitingNextPageRenderers() {
                 AddChild(renderer);
             }
         }
+
+        private bool UpdateForcedPlacement(IRenderer currentRenderer, IRenderer overflowRenderer) {
+            if (true.Equals(currentRenderer.GetProperty<bool?>(Property.FORCED_PLACEMENT))) {
+                return false;
+            }
+            else {
+                overflowRenderer.SetProperty(Property.FORCED_PLACEMENT, true);
+                ILog logger = LogManager.GetLogger(typeof(RootRenderer));
+                if (logger.IsWarnEnabled) {
+                    logger.Warn(MessageFormatUtil.Format(iText.IO.LogMessageConstant.ELEMENT_DOES_NOT_FIT_AREA, ""));
+                }
+                return true;
+            }
+        }
+
+        private bool TryDisableKeepTogether(LayoutResult result, bool rendererIsFloat, RootRendererAreaStateHandler
+             rootRendererStateHandler) {
+            IRenderer toDisableKeepTogether = null;
+            // looking for the most outer keep together element
+            IRenderer current = result.GetCauseOfNothing();
+            while (current != null) {
+                if (true.Equals(current.GetProperty<bool?>(Property.KEEP_TOGETHER))) {
+                    toDisableKeepTogether = current;
+                }
+                current = current.GetParent();
+            }
+            if (toDisableKeepTogether == null) {
+                return false;
+            }
+            // Ideally the disabling of keep together property should be done on the renderers layer,
+            // but due to the problem with renderers tree (parent links from causeOfNothing
+            // may not lead to overflowRenderer) such approach does not work now. So we
+            // disabling keep together on the models layer.
+            toDisableKeepTogether.GetModelElement().SetProperty(Property.KEEP_TOGETHER, false);
+            ILog logger = LogManager.GetLogger(typeof(RootRenderer));
+            if (logger.IsWarnEnabled) {
+                logger.Warn(MessageFormatUtil.Format(iText.IO.LogMessageConstant.ELEMENT_DOES_NOT_FIT_AREA, "KeepTogether property will be ignored."
+                    ));
+            }
+            if (!rendererIsFloat) {
+                rootRendererStateHandler.AttemptGoBackToStoredPreviousStateAndStoreNextState(this);
+            }
+            return true;
+        }
     }
 }

itext.tests/itext.layout.tests/resources/itext/layout/KeepTogetherTest/cmp_contentOverlappingInDivWithKeepTogether.pdf

@@ -1 +1 @@
-451ef20ef4a4d0eabe9ad2184dab4b746c37fa3f
+91bea8fa7cbe39088fe8761c5eb979eb1c5947d2