[java-atk-wrapper] Text: fix getting line start/end

[Samuel Thibault <sthibaul src gnome org>]

commit a6952bb61d18868941d32ab8bd4982e9d1323ab4
Author: Samuel Thibault <samuel thibault ens-lyon org>
Date:   Sun Jul 28 13:02:18 2019 +0200

    Text: fix getting line start/end

 wrapper/org/GNOME/Accessibility/AtkText.java | 70 ++++++++++++++++++++++------
 1 file changed, 57 insertions(+), 13 deletions(-)
---
diff --git a/wrapper/org/GNOME/Accessibility/AtkText.java b/wrapper/org/GNOME/Accessibility/AtkText.java
index 2d39d4f..784d3be 100644
--- a/wrapper/org/GNOME/Accessibility/AtkText.java
+++ b/wrapper/org/GNOME/Accessibility/AtkText.java
@@ -507,16 +507,59 @@ public class AtkText {
                return end;
        }
 
+       private int getNextLineStart (int offset, String str) {
+               int max = str.length();
+               while (offset < max) {
+                       if (str.charAt(offset) == '\n')
+                               return offset+1;
+                       offset += 1;
+               }
+               return offset;
+       }
+
+       private int getPreviousLineStart (int offset, String str) {
+               offset -= 2;
+               while (offset >= 0) {
+                       if (str.charAt(offset) == '\n')
+                               return offset+1;
+                       offset -= 1;
+               }
+               return 0;
+       }
+
+       private int getNextLineEnd (int offset, String str) {
+               int max = str.length();
+               offset += 1;
+               while (offset < max) {
+                       if (str.charAt(offset) == '\n')
+                               return offset;
+                       offset += 1;
+               }
+               return offset;
+       }
+
+       private int getPreviousLineEnd (int offset, String str) {
+               offset -= 1;
+               while (offset >= 0) {
+                       if (str.charAt(offset) == '\n')
+                               return offset;
+                       offset -= 1;
+               }
+               return 0;
+       }
+
        private StringSequence private_get_text_at_offset (int offset,
                        int boundary_type) {
                int char_count = get_character_count();
-               if (offset < 0 || offset >= char_count) {
+               if (offset < 0 || offset > char_count) {
                        return null;
                }
 
                switch (boundary_type) {
                        case AtkTextBoundary.CHAR :
                        {
+                               if (offset == char_count)
+                                       return null;
                                String str = get_text(offset, offset+1);
                                return new StringSequence(str, offset, offset+1);
                        }
@@ -597,21 +640,22 @@ public class AtkText {
                                return new StringSequence(str, start, end);
                        }
                        case AtkTextBoundary.LINE_START :
-                       case AtkTextBoundary.LINE_END :
                        {
-                               BreakIterator lines = BreakIterator.getLineInstance();
-                               String s = get_text(0, char_count);
-                               lines.setText(s);
+                               if (offset == char_count)
+                                       return new StringSequence("", char_count, char_count);
 
-                               int start = lines.preceding(offset);
-                               if (start == BreakIterator.DONE) {
-                                       start = 0;
-                               }
+                               String s = get_text(0, char_count);
+                               int start = getPreviousLineStart(offset+1, s);
+                               int end = getNextLineStart(offset, s);
 
-                               int end = lines.following(offset);
-                               if (end == BreakIterator.DONE) {
-                                       end = s.length();
-                               }
+                               String str = get_text(start, end);
+                               return new StringSequence(str, start, end);
+                       }
+                       case AtkTextBoundary.LINE_END :
+                       {
+                               String s = get_text(0, char_count);
+                               int start = getPreviousLineEnd(offset, s);
+                               int end = getNextLineEnd(offset-1, s);
 
                                String str = get_text(start, end);
                                return new StringSequence(str, start, end);