Make text selection scroll up when a new line enters the buffer.

2 files changed, 38 insertions, 4 deletions

diff --git a/app/src/main/java/org/connectbot/TerminalView.java b/app/src/main/java/org/connectbot/TerminalView.java
index 578dcd7..aec3bc5 100644
--- a/app/src/main/java/org/connectbot/TerminalView.java
+++ b/app/src/main/java/org/connectbot/TerminalView.java
@@ -557,6 +557,15 @@ public class TerminalView extends View implements FontSizeChangedListener {
 				postDelayed(mEventSender, ACCESSIBILITY_EVENT_THRESHOLD);
 			}
 		}
+
+		((Activity) context).runOnUiThread(new Runnable() {
+			@Override
+			public void run() {
+				if (terminalTextViewOverlay != null) {
+					terminalTextViewOverlay.onBufferChanged();
+				}
+			}
+		});
 	}
 
 	private class AccessibilityEventSender implements Runnable {
diff --git a/app/src/main/java/org/connectbot/util/TerminalTextViewOverlay.java b/app/src/main/java/org/connectbot/util/TerminalTextViewOverlay.java
index b64351b..d814f7f 100644
--- a/app/src/main/java/org/connectbot/util/TerminalTextViewOverlay.java
+++ b/app/src/main/java/org/connectbot/util/TerminalTextViewOverlay.java
@@ -55,6 +55,7 @@ public class TerminalTextViewOverlay extends TextView {
 	private ActionMode selectionActionMode;
 	private ClipboardManager clipboard;
 
+	private int oldBufferHeight = 0;
 	private int oldScrollY = -1;
 
 	public TerminalTextViewOverlay(Context context) {
@@ -82,16 +83,15 @@ public class TerminalTextViewOverlay extends TextView {
 		clipboard = (ClipboardManager) getContext().getSystemService(Context.CLIPBOARD_SERVICE);
 	}
 
-	// TODO: optimize: instead of always copying the entire buffer, instead append() as needed.
 	public void refreshTextFromBuffer() {
 		VDUBuffer vb = parent.bridge.getVDUBuffer();
+		int numRows = vb.getBufferSize();
+		int numCols = vb.getColumns() - 1;
+		oldBufferHeight = numRows;
 
 		String line = "";
 		String buffer = "";
 
-		int numRows = vb.getBufferSize();
-		int numCols = vb.getColumns() - 1;
-
 		for (int r = 0; r < numRows && vb.charArray[r] != null; r++) {
 			for (int c = 0; c < numCols; c++) {
 				line += vb.charArray[r][c];
@@ -105,6 +105,31 @@ public class TerminalTextViewOverlay extends TextView {
 		setText(buffer);
 	}
 
+	/**
+	 * If there is a new line in the buffer, add an empty line
+	 * in this TextView, so that selection seems to move up with the
+	 * rest of the buffer.
+	 */
+	public void onBufferChanged() {
+		VDUBuffer vb = parent.bridge.getVDUBuffer();
+		int numRows = vb.getBufferSize();
+		int numNewRows = numRows - oldBufferHeight;
+
+		if (numNewRows <= 0) {
+			return;
+		}
+
+		String newLines = "";
+		for (int i = 0; i < numNewRows; i++) {
+			newLines += "\n";
+		}
+
+		oldScrollY = (vb.getWindowBase() + numNewRows) * getLineHeight();
+		oldBufferHeight = numRows;
+
+		append(newLines);
+	}
+
 	@Override
 	public boolean onPreDraw() {
 		boolean superResult = super.onPreDraw();