Fix tabs to not overwrite cells

termux · Feb 25, 2016 · 6ca055b · 6ca055b
1 parent ce7ad53
commit 6ca055b
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Showing 4 changed files with 30 additions and 17 deletions.
diff --git a/app/build.gradle b/app/build.gradle
@@ -18,8 +18,8 @@ android {
  applicationId "com.termux"
  minSdkVersion 21
  targetSdkVersion 23
- versionCode 29
- versionName "0.29"
+ versionCode 30
+ versionName "0.30"
  }
 
  buildTypes {

diff --git a/app/src/main/java/com/termux/terminal/TerminalEmulator.java b/app/src/main/java/com/termux/terminal/TerminalEmulator.java
@@ -425,9 +425,9 @@ private void processByte(byte byteToProcess) {
  processCodePoint((codePoint & 0x7F) + 0x40);
  } else {
  switch (Character.getType(codePoint)) {
-  case Character.UNASSIGNED:
-  case Character.SURROGATE:
-  codePoint = UNICODE_REPLACEMENT_CHAR;
+ case Character.UNASSIGNED:
+ case Character.SURROGATE:
+ codePoint = UNICODE_REPLACEMENT_CHAR;
  }
  processCodePoint(codePoint);
  }
@@ -474,16 +474,19 @@ public void processCodePoint(int b) {
  else
  mSession.onBell();
  break;
- case 8: // BS
- setCursorCol(Math.max(mLeftMargin, mCursorCol - 1));
- break;
- case 9: // Horizontal tab - move to next tab stop, but not past edge of screen
- int nextTabStop = nextTabStop(1);
- while (mCursorCol < nextTabStop) {
- // Emit newlines to get background color right.
- processCodePoint(' ');
- }
- break;
+ case 8: // Backspace (BS, ^H).
+ setCursorCol(Math.max(mLeftMargin, mCursorCol - 1));
+ break;
+ case 9: // Horizontal tab (HT, \t) - move to next tab stop, but not past edge of screen
+ // XXX: Should perhaps use color if writing to new cells. Try with
+ // printf "\033[41m\tXX\033[0m\n"
+ // The OSX Terminal.app colors the spaces from the tab red, but xterm does not.
+ // Note that Terminal.app only colors on new cells, in e.g.
+ // printf "\033[41m\t\r\033[42m\tXX\033[0m\n"
+ // the first cells are created with a red background, but when tabbing over
+ // them again with a green background they are not overwritten.
+ mCursorCol = nextTabStop(1);
+ break;
  case 10: // Line feed (LF, \n).
  case 11: // Vertical tab (VT, \v).
  case 12: // Form feed (FF, \f).
@@ -1331,7 +1334,7 @@ private void doCsi(int b) {
  continueSequence(ESC_CSI_ARGS_ASTERIX);
  break;
  case '@': {
- // "CSI{n}@" -  Insert ${n} space characters (ICH) - http://www.vt100.net/docs/vt510-rm/ICH.
+ // "CSI{n}@" - Insert ${n} space characters (ICH) - http://www.vt100.net/docs/vt510-rm/ICH.
  mAboutToAutoWrap = false;
  int columnsAfterCursor = mColumns - mCursorCol;
  int spacesToInsert = Math.min(getArg0(1), columnsAfterCursor);

diff --git a/app/src/test/java/com/termux/terminal/CursorAndScreenTest.java b/app/src/test/java/com/termux/terminal/CursorAndScreenTest.java
@@ -163,7 +163,12 @@ public void testReportCursorPosition() {
  }
  }
 
- public void testHorizontalTabColorsBackground() {
+ /**
+ * See comments on horizontal tab handling in TerminalEmulator.java.
+ *
+ * We do not want to color already written cells when tabbing over them.
+ */
+ public void DISABLED_testHorizontalTabColorsBackground() {
  withTerminalSized(10, 3).enterString("\033[48;5;15m").enterString("\t");
  assertCursorAt(0, 8);
  for (int i = 0; i < 10; i++) {

diff --git a/app/src/test/java/com/termux/terminal/TerminalTest.java b/app/src/test/java/com/termux/terminal/TerminalTest.java
@@ -258,4 +258,9 @@ public void testAutomargins() throws UnsupportedEncodingException {
  withTerminalSized(3, 3).enterString("abc\r ").assertLinesAre(" bc", " ", " ").assertCursorAt(0, 1);
  }
 
+ public void testTab() {
+ withTerminalSized(11, 2).enterString("01234567890\r\tXX").assertLinesAre("01234567XX0", " ");
+ withTerminalSized(11, 2).enterString("01234567890\033[44m\r\tXX").assertLinesAre("01234567XX0", " ");
+ }
+
 }