KeepTogether disable for not fit in keepTogether tree fix

DEVSIX-3468

Author: BezrukovM

layout/src/main/java/com/itextpdf/layout/renderer/RootRenderer.java

@@ -168,35 +168,16 @@ public void addChild(IRenderer renderer) {
                         }
                     } else {
                         if (currentArea.isEmptyArea() && result.getAreaBreak() == null) {
-                            if (Boolean.TRUE.equals(result.getOverflowRenderer().getModelElement().<Boolean>getProperty(Property.KEEP_TOGETHER))) {
-                                result.getOverflowRenderer().getModelElement().setProperty(Property.KEEP_TOGETHER, false);
-                                Logger logger = LoggerFactory.getLogger(RootRenderer.class);
-                                logger.warn(MessageFormatUtil.format(LogMessageConstant.ELEMENT_DOES_NOT_FIT_AREA, "KeepTogether property will be ignored."));
-                                if (!rendererIsFloat) {
-                                    rootRendererStateHandler.attemptGoBackToStoredPreviousStateAndStoreNextState(this);
-                                }
-                            } else if (null != result.getCauseOfNothing() && Boolean.TRUE.equals(result.getCauseOfNothing().<Boolean>getProperty(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().<Boolean>getOwnProperty(Property.KEEP_TOGETHER)) {
-                                    parent = ((AbstractRenderer) theDeepestKeptTogether).parent;
-                                    if (parent == null) {
-                                        break;
-                                    }
-                                    theDeepestKeptTogether = parent;
-                                }
-                                theDeepestKeptTogether.getModelElement().setProperty(Property.KEEP_TOGETHER, false);
-                                Logger logger = LoggerFactory.getLogger(RootRenderer.class);
-                                logger.warn(MessageFormatUtil.format(LogMessageConstant.ELEMENT_DOES_NOT_FIT_AREA, "KeepTogether property of inner element will be ignored."));
-                                if (!rendererIsFloat) {
-                                    rootRendererStateHandler.attemptGoBackToStoredPreviousStateAndStoreNextState(this);
-                                }
-                            } else if (!Boolean.TRUE.equals(renderer.<Boolean>getProperty(Property.FORCED_PLACEMENT))) {
-                                result.getOverflowRenderer().setProperty(Property.FORCED_PLACEMENT, true);
-                                Logger logger = LoggerFactory.getLogger(RootRenderer.class);
-                                logger.warn(MessageFormatUtil.format(LogMessageConstant.ELEMENT_DOES_NOT_FIT_AREA, ""));
-                            } else {
+                            boolean keepTogetherChanged = tryDisableKeepTogether(result,
+                                    rendererIsFloat, rootRendererStateHandler);
+
+                            boolean areKeepTogetherAndForcedPlacementBothNotChanged = !keepTogetherChanged;
+                            if (areKeepTogetherAndForcedPlacementBothNotChanged) {
+                                areKeepTogetherAndForcedPlacementBothNotChanged =
+                                        ! updateForcedPlacement(renderer, result.getOverflowRenderer());
+                            }
+
+                            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.
@@ -490,4 +471,51 @@ private void addWaitingNextPageRenderers() {
             addChild(renderer);
         }
     }
+
+    private boolean updateForcedPlacement(IRenderer currentRenderer, IRenderer overflowRenderer) {
+        if (Boolean.TRUE.equals(currentRenderer.<Boolean>getProperty(Property.FORCED_PLACEMENT))) {
+            return false;
+        } else {
+            overflowRenderer.setProperty(Property.FORCED_PLACEMENT, true);
+            Logger logger = LoggerFactory.getLogger(RootRenderer.class);
+            if (logger.isWarnEnabled()) {
+                logger.warn(MessageFormatUtil.format(LogMessageConstant.ELEMENT_DOES_NOT_FIT_AREA, ""));
+            }
+            return true;
+        }
+    }
+
+    private boolean tryDisableKeepTogether(LayoutResult result,
+            boolean rendererIsFloat, RootRendererAreaStateHandler rootRendererStateHandler) {
+        IRenderer toDisableKeepTogether = null;
+
+        // looking for the most outer keep together element
+        IRenderer current = result.getCauseOfNothing();
+        while (current != null) {
+            if (Boolean.TRUE.equals(current.<Boolean>getProperty(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);
+        Logger logger = LoggerFactory.getLogger(RootRenderer.class);
+        if (logger.isWarnEnabled()) {
+            logger.warn(MessageFormatUtil.format(
+                    LogMessageConstant.ELEMENT_DOES_NOT_FIT_AREA,
+                    "KeepTogether property will be ignored."));
+        }
+        if (!rendererIsFloat) {
+            rootRendererStateHandler.attemptGoBackToStoredPreviousStateAndStoreNextState(this);
+        }
+        return true;
+    }
 }

layout/src/test/java/com/itextpdf/layout/KeepTogetherTest.java

@@ -1028,10 +1028,10 @@ public void smallFloatInsideKeptTogetherTableTest02() throws IOException, Interr
 
     @Test
     @LogMessages(messages = {
-            @LogMessage(messageTemplate = LogMessageConstant.ELEMENT_DOES_NOT_FIT_AREA, count = 2)
+            @LogMessage(messageTemplate = LogMessageConstant.ELEMENT_DOES_NOT_FIT_AREA)
     })
-    public void contentOverlappingInDivWithKeepTogetherTest() throws IOException, InterruptedException {
-        String filename = "contentOverlappingInDivWithKeepTogether.pdf";
+    public void keepTogetherTreeWithParentNotFitOnDocumentTest() throws IOException, InterruptedException {
+        String filename = "keepTogetherTreeWithParentNotFitOnDocument.pdf";
         String outFile = destinationFolder + filename;
         String cmpFileName = sourceFolder + "cmp_" + filename;
 
@@ -1060,10 +1060,10 @@ public void contentOverlappingInDivWithKeepTogetherTest() throws IOException, In
 
     @Test
     @LogMessages(messages = {
-            @LogMessage(messageTemplate = LogMessageConstant.ELEMENT_DOES_NOT_FIT_AREA, count = 2)
+            @LogMessage(messageTemplate = LogMessageConstant.ELEMENT_DOES_NOT_FIT_AREA)
     })
-    public void missContentAndOverlappingInDivNoKeepTogetherTest() throws IOException, InterruptedException {
-        String filename = "missContentAndOverlappingInDivNoKeepTogether.pdf";
+    public void keepTogetherSubTreeWithParentNotFitOnDocumentTest() throws IOException, InterruptedException {
+        String filename = "keepTogetherSubTreeWithParentNotFitOnDocument.pdf";
         String outFile = destinationFolder + filename;
         String cmpFileName = sourceFolder + "cmp_" + filename;
 
@@ -1094,10 +1094,45 @@ public void missContentAndOverlappingInDivNoKeepTogetherTest() throws IOExceptio
 
     @Test
     @LogMessages(messages = {
-            @LogMessage(messageTemplate = LogMessageConstant.ELEMENT_DOES_NOT_FIT_AREA, count = 2)
+            @LogMessage(messageTemplate = LogMessageConstant.ELEMENT_DOES_NOT_FIT_AREA)
+    })
+    public void keepTogetherSubTreeWithChildKeepTogetherFalseAndParentNotFitOnDocumentTest()
+            throws IOException, InterruptedException {
+        String filename = "keepTogetherSubTreeWithChildKeepTogetherFalseAndParentNotFitOnDocument.pdf";
+        String outFile = destinationFolder + filename;
+        String cmpFileName = sourceFolder + "cmp_" + filename;
+
+        try (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);
+        }
+
+        Assert.assertNull(new CompareTool().compareByContent(outFile, cmpFileName, destinationFolder));
+    }
+
+    @Test
+    @LogMessages(messages = {
+            @LogMessage(messageTemplate = LogMessageConstant.ELEMENT_DOES_NOT_FIT_AREA)
     })
-    public void contentOverlappingDivKeepTogetherInRectTest() throws IOException, InterruptedException {
-        String filename = "contentOverlappingDivKeepTogetherInRect.pdf";
+    public void keepTogetherTreeWithParentNotFitOnPageCanvasTest() throws IOException, InterruptedException {
+        String filename = "keepTogetherTreeWithParentNotFitOnPageCanvas.pdf";
         String outFile = destinationFolder + filename;
         String cmpFileName = sourceFolder + "cmp_" + filename;