Add scrollback support.

Switch terminal rendering to use ListView, splitting each row into a
TerminalLineView item.  This leverages existing ListView display list
optimizations when scrolling, and gives us fling and overscroll for
free.  However, the simple case of a single line scrolling requires
an entire screen rebind.

Added locking between I/O thread and UI thread to provide consistent
view of terminal state.  Snap to current upstream libvterm, which has
updated scrollback API.  Examine full cell style when building runs.

Address terminals using "keys" instead of indicies, since ordering
can shift.  Save and restore instance state to remember scrollback
position.  Avoid crashing after closing last terminal.

Remove unused callbacks.

Bug: 8332387
Change-Id: I06468d16ae8e1ff8ac79b7115c7cb3f9434b3c0d

1 files changed, 41 insertions, 7 deletions

diff --git a/src/com/android/terminal/TerminalActivity.java b/src/com/android/terminal/TerminalActivity.java
index 99d2be6..dd94d74 100644
--- a/src/com/android/terminal/TerminalActivity.java
+++ b/src/com/android/terminal/TerminalActivity.java
@@ -16,6 +16,8 @@
 
 package com.android.terminal;
 
+import static com.android.terminal.Terminal.TAG;
+
 import android.app.Activity;
 import android.content.ComponentName;
 import android.content.Context;
@@ -23,10 +25,12 @@ import android.content.Intent;
 import android.content.ServiceConnection;
 import android.os.Bundle;
 import android.os.IBinder;
+import android.os.Parcelable;
 import android.support.v4.view.PagerAdapter;
 import android.support.v4.view.PagerTitleStrip;
 import android.support.v4.view.ViewPager;
 import android.util.Log;
+import android.util.SparseArray;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.view.View;
@@ -37,7 +41,6 @@ import android.view.ViewGroup;
  * {@link TerminalService}.
  */
 public class TerminalActivity extends Activity {
-    private static final String TAG = "Terminal";
 
     private TerminalService mService;
 
@@ -59,6 +62,7 @@ public class TerminalActivity extends Activity {
 
             // Bind UI to known terminals
             mTermAdapter.notifyDataSetChanged();
+            invalidateOptionsMenu();
         }
 
         @Override
@@ -69,6 +73,9 @@ public class TerminalActivity extends Activity {
     };
 
     private final PagerAdapter mTermAdapter = new PagerAdapter() {
+        private SparseArray<SparseArray<Parcelable>>
+                mSavedState = new SparseArray<SparseArray<Parcelable>>();
+
         @Override
         public int getCount() {
             if (mService != null) {
@@ -80,9 +87,17 @@ public class TerminalActivity extends Activity {
 
         @Override
         public Object instantiateItem(ViewGroup container, int position) {
-            final Terminal term = mService.getTerminals().get(position);
             final TerminalView view = new TerminalView(container.getContext());
+            view.setId(android.R.id.list);
+
+            final Terminal term = mService.getTerminals().valueAt(position);
             view.setTerminal(term);
+
+            final SparseArray<Parcelable> state = mSavedState.get(term.key);
+            if (state != null) {
+                view.restoreHierarchyState(state);
+            }
+
             container.addView(view);
             return view;
         }
@@ -90,13 +105,24 @@ public class TerminalActivity extends Activity {
         @Override
         public void destroyItem(ViewGroup container, int position, Object object) {
             final TerminalView view = (TerminalView) object;
+
+            final int key = view.getTerminal().key;
+            SparseArray<Parcelable> state = mSavedState.get(key);
+            if (state == null) {
+                state = new SparseArray<Parcelable>();
+                mSavedState.put(key, state);
+            }
+            view.saveHierarchyState(state);
+
             view.setTerminal(null);
             container.removeView(view);
         }
 
         @Override
         public int getItemPosition(Object object) {
-            final int index = mService.getTerminals().indexOf(object);
+            final TerminalView view = (TerminalView) object;
+            final int key = view.getTerminal().key;
+            final int index = mService.getTerminals().indexOfKey(key);
             if (index == -1) {
                 return POSITION_NONE;
             } else {
@@ -111,7 +137,7 @@ public class TerminalActivity extends Activity {
 
         @Override
         public CharSequence getPageTitle(int position) {
-            return mService.getTerminals().get(position).getTitle();
+            return mService.getTerminals().valueAt(position).getTitle();
         }
     };
 
@@ -147,21 +173,29 @@ public class TerminalActivity extends Activity {
     }
 
     @Override
+    public boolean onPrepareOptionsMenu(Menu menu) {
+        super.onPrepareOptionsMenu(menu);
+        menu.findItem(R.id.menu_close_tab).setEnabled(mTermAdapter.getCount() > 0);
+        return true;
+    }
+
+    @Override
     public boolean onOptionsItemSelected(MenuItem item) {
         switch (item.getItemId()) {
             case R.id.menu_new_tab: {
                 mService.createTerminal();
                 mTermAdapter.notifyDataSetChanged();
+                invalidateOptionsMenu();
                 final int index = mService.getTerminals().size() - 1;
                 mPager.setCurrentItem(index, true);
                 return true;
             }
             case R.id.menu_close_tab: {
                 final int index = mPager.getCurrentItem();
-                final Terminal term = mService.getTerminals().get(index);
-                mService.destroyTerminal(term);
-                // TODO: ask adamp about buggy zero item behavior
+                final int key = mService.getTerminals().keyAt(index);
+                mService.destroyTerminal(key);
                 mTermAdapter.notifyDataSetChanged();
+                invalidateOptionsMenu();
                 return true;
             }
         }