[diff/merge] IDEA-59513 scroll to the first conflicting change after applying "all non-conflicting changes"

Let LineBlocks#getBeginnings return only applied changes, and use this method to scroll in the merge tool to ignore applied changes when scrolling to the first change.

platform/platform-impl/src/com/intellij/openapi/diff/impl/incrementalMerge/ui/ApplyNonConflicts.java

@@ -22,17 +22,22 @@ import com.intellij.openapi.actionSystem.DataContext;
 import com.intellij.openapi.diff.DiffBundle;
 import com.intellij.openapi.diff.impl.incrementalMerge.Change;
 import com.intellij.openapi.diff.impl.incrementalMerge.MergeList;
+import com.intellij.openapi.diff.impl.util.DiffPanelOuterComponent;
 import com.intellij.openapi.project.DumbAware;
 import com.intellij.util.containers.ContainerUtil;
 import com.intellij.util.containers.FilteringIterator;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
 
 public class ApplyNonConflicts extends AnAction implements DumbAware {
-  public ApplyNonConflicts() {
+  @Nullable private final DiffPanelOuterComponent myDiffPanel;
+
+  public ApplyNonConflicts(@Nullable DiffPanelOuterComponent diffPanel) {
     super(DiffBundle.message("merge.dialog.apply.all.non.conflicting.changes.action.name"), null, AllIcons.Diff.ApplyNotConflicts);
+    myDiffPanel = diffPanel;
   }
 
   public void actionPerformed(AnActionEvent e) {
@@ -41,6 +46,9 @@ public class ApplyNonConflicts extends AnAction implements DumbAware {
     for (Change change : notConflicts) {
       Change.apply(change, MergeList.BRANCH_SIDE);
     }
+    if (myDiffPanel != null) {
+      myDiffPanel.requestScrollEditors();
+    }
   }
 
   public void update(AnActionEvent e) {

platform/platform-impl/src/com/intellij/openapi/diff/impl/incrementalMerge/ui/MergePanel2.java

@@ -145,7 +145,7 @@ public class MergePanel2 implements DiffViewer {
         toolbar.addAction(new OpenPartialDiffAction(1, 2, AllIcons.Diff.RightDiff));
         toolbar.addAction(new OpenPartialDiffAction(0, 2, AllIcons.Diff.BranchDiff));
         toolbar.addSeparator();
-        toolbar.addAction(new ApplyNonConflicts());
+        toolbar.addAction(new ApplyNonConflicts(myPanel));
         toolbar.addSeparator();
         toolbar.addAction(new MergeToolSettingsAction(getEditors()));
       }
@@ -414,7 +414,7 @@ public class MergePanel2 implements DiffViewer {
     private int[] getPrimaryBeginnings(DiffDividerPaint paint) {
       FragmentSide primarySide = paint.getLeftSide();
       LOG.assertTrue(getEditor(1) == paint.getSides().getEditor(primarySide));
-      return paint.getSides().getLineBlocks().getBeginnings(primarySide);
+      return paint.getSides().getLineBlocks().getBeginnings(primarySide, true);
     }
   }
 

platform/platform-impl/src/com/intellij/openapi/diff/impl/splitter/LineBlocks.java

@@ -22,7 +22,7 @@ import com.intellij.openapi.diff.impl.highlighting.FragmentSide;
 import com.intellij.openapi.diff.impl.incrementalMerge.Change;
 import com.intellij.openapi.diff.impl.incrementalMerge.ChangeList;
 import com.intellij.openapi.diff.impl.util.TextDiffType;
-import com.intellij.util.containers.IntArrayList;
+import com.intellij.util.ArrayUtil;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.*;
@@ -61,16 +61,33 @@ public class LineBlocks {
     return getBeginnings(FragmentSide.SIDE1).length;
   }
 
+  /**
+   * Get beginnings of all the changes from the specified side.
+   * @param side Side of the changes.
+   */
   public int[] getBeginnings(FragmentSide side) {
-    IntArrayList result = new IntArrayList(getIntervals(side).length);
+    return getBeginnings(side, false);
+  }
+
+  /**
+   * Get beginnings of the changes from the specified side.
+   * @param side          Side of the changes.
+   * @param unappliedOnly If true - only unapplied changes will be considered, if false - all changes (both applied and not applied).
+   */
+  public int[] getBeginnings(FragmentSide side, boolean unappliedOnly) {
+    List<Integer> result = new ArrayList<Integer>(myDiffs.size());
     int previousBeginning = Integer.MIN_VALUE;
-    Interval[] sideIntervals = getIntervals(side);
-    for (Interval sideInterval : sideIntervals) {
-      int start = sideInterval.getStart();
-      if (start != previousBeginning) result.add(start);
-      previousBeginning = start;
+
+    for (Diff diff : myDiffs) {
+      if (!unappliedOnly || !diff.getDiffType().isApplied()) {
+        Interval interval = diff.getInterval(side);
+        int start = interval.getStart();
+        if (start != previousBeginning) result.add(start);
+        previousBeginning = start;
+      }
     }
-    return result.toArray();
+
+    return ArrayUtil.toIntArray(result);
   }
 
   static int getMaxStartedIndex(Interval[] intervals, int start) {