Fix keeping caret on screen with preceding inlay

src/com/maddyhome/idea/vim/group/DigraphGroup.java

@@ -81,7 +81,7 @@ public class DigraphGroup {
   }
 
   private void showDigraphs(@NotNull Editor editor) {
-    int width = EditorHelper.getScreenWidth(editor);
+    int width = EditorHelper.getApproximateScreenWidth(editor);
     if (width < 10) {
       width = 80;
     }

src/com/maddyhome/idea/vim/group/MotionGroup.java

@@ -171,36 +171,40 @@ public class MotionGroup {
   private static void moveCaretToView(@NotNull Editor editor) {
     final int scrollOffset = getNormalizedScrollOffset(editor);
 
-    int topVisualLine = EditorHelper.getVisualLineAtTopOfScreen(editor);
-    int bottomVisualLine = EditorHelper.getVisualLineAtBottomOfScreen(editor);
-    int caretVisualLine = editor.getCaretModel().getVisualPosition().line;
-    int newVisualLine = caretVisualLine;
+    final int topVisualLine = EditorHelper.getVisualLineAtTopOfScreen(editor);
+    final int bottomVisualLine = EditorHelper.getVisualLineAtBottomOfScreen(editor);
+    final int caretVisualLine = editor.getCaretModel().getVisualPosition().line;
+    final int newVisualLine;
     if (caretVisualLine < topVisualLine + scrollOffset) {
       newVisualLine = EditorHelper.normalizeVisualLine(editor, topVisualLine + scrollOffset);
     }
     else if (caretVisualLine >= bottomVisualLine - scrollOffset) {
       newVisualLine = EditorHelper.normalizeVisualLine(editor, bottomVisualLine - scrollOffset);
     }
-
-    int sideScrollOffset = OptionsManager.INSTANCE.getSidescrolloff().value();
-    int width = EditorHelper.getScreenWidth(editor);
-    if (sideScrollOffset > width / 2) {
-      sideScrollOffset = width / 2;
+    else {
+      newVisualLine = caretVisualLine;
     }
 
-    int col = editor.getCaretModel().getVisualPosition().column;
-    int oldColumn = col;
+    final int sideScrollOffset = getNormalizedSideScrollOffset(editor);
+
+    final int oldColumn = editor.getCaretModel().getVisualPosition().column;
+    int col = oldColumn;
     if (col >= EditorHelper.getLineLength(editor) - 1) {
       col = UserDataManager.getVimLastColumn(editor.getCaretModel().getPrimaryCaret());
     }
-    int visualColumn = EditorHelper.getVisualColumnAtLeftOfScreen(editor, newVisualLine);
+
+    final int leftVisualColumn = EditorHelper.getVisualColumnAtLeftOfScreen(editor, newVisualLine);
+    final int rightVisualColumn = EditorHelper.getVisualColumnAtRightOfScreen(editor, newVisualLine);
+
     int caretColumn = col;
     int newColumn = caretColumn;
-    if (caretColumn < visualColumn + sideScrollOffset) {
-      newColumn = visualColumn + sideScrollOffset;
+
+    // TODO: Visual column arithmetic will be inaccurate as it include columns for inlays and folds
+    if (caretColumn < leftVisualColumn + sideScrollOffset) {
+      newColumn = leftVisualColumn + sideScrollOffset;
     }
-    else if (caretColumn >= visualColumn + width - sideScrollOffset) {
-      newColumn = visualColumn + width - sideScrollOffset - 1;
+    else if (caretColumn > rightVisualColumn - sideScrollOffset) {
+      newColumn = rightVisualColumn - sideScrollOffset;
     }
 
     if (newVisualLine == caretVisualLine && newColumn != caretColumn) {
@@ -270,10 +274,15 @@ public class MotionGroup {
   }
 
   private static int getNormalizedScrollOffset(final @NotNull Editor editor) {
-    int scrollOffset = OptionsManager.INSTANCE.getScrolloff().value();
+    final int scrollOffset = OptionsManager.INSTANCE.getScrolloff().value();
     return EditorHelper.normalizeScrollOffset(editor, scrollOffset);
   }
 
+  private static int getNormalizedSideScrollOffset(final @NotNull Editor editor) {
+    final int sideScrollOffset = OptionsManager.INSTANCE.getSidescrolloff().value();
+    return EditorHelper.normalizeSideScrollOffset(editor, sideScrollOffset);
+  }
+
   public static void moveCaret(@NotNull Editor editor, @NotNull Caret caret, int offset) {
     if (offset < 0 || offset > editor.getDocument().getTextLength() || !caret.isValid()) return;
 
@@ -590,7 +599,7 @@ public class MotionGroup {
 
   public boolean scrollCaretColumnToFirstScreenColumn(@NotNull Editor editor) {
     final VisualPosition caretVisualPosition = editor.getCaretModel().getVisualPosition();
-    final int scrollOffset = Math.min(OptionsManager.INSTANCE.getSidescrolloff().value(), EditorHelper.getScreenWidth(editor) / 2);
+    final int scrollOffset = getNormalizedSideScrollOffset(editor);
     // TODO: Should the offset be applied to visual columns? This includes inline inlays and folds
     final int column = Math.max(0, caretVisualPosition.column - scrollOffset);
     EditorHelper.scrollColumnToLeftOfScreen(editor, caretVisualPosition.line, column);
@@ -599,7 +608,7 @@ public class MotionGroup {
 
   public boolean scrollCaretColumnToLastScreenColumn(@NotNull Editor editor) {
     final VisualPosition caretVisualPosition = editor.getCaretModel().getVisualPosition();
-    final int scrollOffset = Math.min(OptionsManager.INSTANCE.getSidescrolloff().value(), EditorHelper.getScreenWidth(editor) / 2);
+    final int scrollOffset = getNormalizedSideScrollOffset(editor);
     // TODO: Should the offset be applied to visual columns? This includes inline inlays and folds
     final int column = EditorHelper.normalizeVisualColumn(editor, caretVisualPosition.line, caretVisualPosition.column + scrollOffset, false);
     EditorHelper.scrollColumnToRightOfScreen(editor, caretVisualPosition.line, column);
@@ -751,8 +760,8 @@ public class MotionGroup {
     final int currentVisualRightColumn = EditorHelper.getVisualColumnAtRightOfScreen(editor, position.line);
     final int caretColumn = position.column;
 
-    final int halfWidth = EditorHelper.getScreenWidth(editor) / 2;
-    final int scrollOffset = Math.min(OptionsManager.INSTANCE.getSidescrolloff().value(), halfWidth);
+    final int halfWidth = EditorHelper.getApproximateScreenWidth(editor) / 2;
+    final int scrollOffset = getNormalizedSideScrollOffset(editor);
 
     final EnumSet<CommandFlags> flags = CommandState.getInstance(editor).getExecutingCommandFlags();
     final boolean allowSidescroll = !flags.contains(CommandFlags.FLAG_IGNORE_SIDE_SCROLL_JUMP);
@@ -907,7 +916,7 @@ public class MotionGroup {
   }
 
   public int moveCaretToMiddleColumn(@NotNull Editor editor, @NotNull Caret caret) {
-    final int width = EditorHelper.getScreenWidth(editor) / 2;
+    final int width = EditorHelper.getApproximateScreenWidth(editor) / 2;
     final int len = EditorHelper.getLineLength(editor);
 
     return moveCaretToColumn(editor, caret, Math.max(0, Math.min(len - 1, width)), false);

src/com/maddyhome/idea/vim/helper/EditorHelper.java

@@ -183,8 +183,18 @@ public class EditorHelper {
   }
 
   /**
-   * Gets the number of lines than can be displayed on the screen at one time. This is rounded down to the
-   * nearest whole line if there is a partial line visible at the bottom of the screen.
+   * Best efforts to ensure the side scroll offset doesn't overlap itself and remains a sensible value. Inline inlays
+   * can cause this to work incorrectly.
+   * @param editor The editor to use to normalize the side scroll offset
+   * @param sideScrollOffset The value of the 'sidescroll' option
+   * @return The side scroll offset value to use
+   */
+  public static int normalizeSideScrollOffset(final @NotNull Editor editor, int sideScrollOffset) {
+    return Math.min(sideScrollOffset, getApproximateScreenWidth(editor) / 2);
+  }
+
+  /**
+   * Gets the number of lines than can be displayed on the screen at one time.
    *
    * Note that this value is only approximate and should be avoided whenever possible!
    *
@@ -192,24 +202,20 @@ public class EditorHelper {
    * @return The number of screen lines
    */
   private static int getApproximateScreenHeight(final @NotNull Editor editor) {
-    int lh = editor.getLineHeight();
-    Rectangle area = getVisibleArea(editor);
-    int height = area.y + area.height - getVisualLineAtTopOfScreen(editor) * lh;
-    return height / lh;
+    return getVisibleArea(editor).height / editor.getLineHeight();
   }
 
   /**
-   * Gets the number of characters that are visible on a screen line
+   * Gets the number of characters that are visible on a screen line, based on screen width and assuming a fixed width
+   * font. It does not include inlays or folds.
+   *
+   * Note that this value is only approximate and should be avoided whenever possible!
    *
    * @param editor The editor
    * @return The number of screen columns
    */
-  public static int getScreenWidth(final @NotNull Editor editor) {
-    Rectangle rect = getVisibleArea(editor);
-    Point pt = new Point(rect.width, 0);
-    VisualPosition vp = editor.xyToVisualPosition(pt);
-
-    return vp.column;
+  public static int getApproximateScreenWidth(final @NotNull Editor editor) {
+    return getVisibleArea(editor).width / EditorUtil.getPlainSpaceWidth(editor);
   }
 
   /**

src/com/maddyhome/idea/vim/option/OptionsManager.kt

@@ -314,7 +314,7 @@ object OptionsManager {
     cols.sortBy { it.name }
     extra.sortBy { it.name }
 
-    var width = EditorHelper.getScreenWidth(editor)
+    var width = EditorHelper.getApproximateScreenWidth(editor)
     if (width < 20) {
       width = 80
     }

test/org/jetbrains/plugins/ideavim/action/scroll/ScrollColumnRightActionTest.kt

@@ -146,4 +146,21 @@ class ScrollColumnRightActionTest : VimTestCase() {
     typeText(parseKeys("zh"))   //           9
     assertVisibleLineBounds(0, 49, 128) // 80 characters
   }
+
+  fun `test scroll column to right with preceding inline inlay moves cursor at end of screen`() {
+    configureByColumns(200)
+    val inlay = myFixture.editor.inlayModel.addInlineElement(90, false, HintRenderer("test:"))!!
+    typeText(parseKeys("100|", "ze", "zh"))
+    assertPosition(0, 98)
+    assertVisibleLineBounds(0, 24, 98)
+    typeText(parseKeys("zh"))
+    assertPosition(0, 97)
+    assertVisibleLineBounds(0, 23, 97)
+    typeText(parseKeys("zh"))
+    assertPosition(0, 96)
+    assertVisibleLineBounds(0, 22, 96)
+    typeText(parseKeys("zh"))
+    assertPosition(0, 95)
+    assertVisibleLineBounds(0, 21, 95)
+  }
 }