Overhaul the way display history is memorized.

In a nutshell: a UnicodeMapActivity.Display stores the kind of content
the ListView can have (the root, a Unicode range, or a search result).
The doDisplay() method actually performs such a display, and is
generally called after saveDisplay() which stores the current display
(curDisp) in the display stack together with position information.

1 files changed, 113 insertions, 79 deletions

diff --git a/src/org/madore/android/unicodeMap/UnicodeMapActivity.java b/src/org/madore/android/unicodeMap/UnicodeMapActivity.java
index d260ff6..9f8194f 100644
--- a/src/org/madore/android/unicodeMap/UnicodeMapActivity.java
+++ b/src/org/madore/android/unicodeMap/UnicodeMapActivity.java
@@ -26,26 +26,62 @@ import android.app.ProgressDialog;
 public final class UnicodeMapActivity extends ListActivity {
 
     protected UnicodeDatabase db;
+    protected ListView lv;
 
-    protected class ViewHistory {
-	public final UnicodeArrayAdapter adapter;
-	public final int selPosition;
-	public final int yOffset;
-	public final CharSequence title;
-	public ViewHistory(UnicodeArrayAdapter adapter,
-			   int selPosition, int yOffset,
-			   CharSequence title) {
-	    this.adapter = adapter;
+    protected static abstract class Display {
+	protected String title;
+	public Display(String title) { this.title = title; }
+	public final String getTitle() { return this.title; }
+    }
+    protected static class RootDisplay extends Display {
+	public RootDisplay() { super(null); }
+    }
+    protected static class RangeDisplay extends Display {
+	protected int from;  protected int to;
+	public RangeDisplay(String title, int from, int to) {
+	    super(title);
+	    this.from = from;  this.to = to;
+	}
+	public RangeDisplay(UnicodeCharacter.Range rng) {
+	    super(rng.getDescr());
+	    this.from = rng.getFrom();  this.to = rng.getTo();
+	}
+	public int getFrom() { return this.from; }
+	public int getTo() { return this.to; }
+    }
+    protected static class SearchDisplay extends Display {
+	protected String like;  protected int limit;
+	protected int sizeHint;
+	public SearchDisplay(String title, String like, int limit) {
+	    super(title);
+	    this.like = like;  this.limit = limit;
+	    this.sizeHint = 128;
+	}
+	public void setSizeHint(int hint) { this.sizeHint = hint; }
+	public String getLike() { return this.like; }
+	public int getLimit() { return this.limit; }
+	public int getSizeHint() { return this.sizeHint; }
+    }
+
+    protected static class DisplayAndPosition {
+	protected Display disp;
+	protected int selPosition;  protected int yOffset;
+	public DisplayAndPosition(Display disp,
+				  int selPosition, int yOffset) {
+	    this.disp = disp;
 	    this.selPosition = selPosition;
 	    this.yOffset = yOffset;
-	    this.title = title;
 	}
+	public Display getDisp() { return this.disp; }
+	public int getSelPosition() { return this.selPosition; }
+	public int getYOffset() { return this.yOffset; }
     }
 
-    protected final List<ViewHistory> historyStack
-	= new ArrayList<ViewHistory>(10);
+    protected Display curDisp;
+    protected final List<DisplayAndPosition> dispHistory
+	= new ArrayList<DisplayAndPosition>(10);
 
-    EditText textForm;
+    protected EditText textForm;
 
     protected void launchPopulation() {
 	final ProgressDialog progress = new ProgressDialog(this);
@@ -75,26 +111,18 @@ public final class UnicodeMapActivity extends ListActivity {
 	thr.start();
     }
 
-    protected void saveView(View selView, int selPosition) {
-	final ListView lv = getListView();
+    protected void saveDisplay(View selView, int selPosition) {
 	lv.clearTextFilter();
-	final UnicodeArrayAdapter adapter
-	    = (UnicodeArrayAdapter) lv.getAdapter();
 	final int yOffset;
 	if ( selView != null )
 	    yOffset = selView.getTop();
 	else
 	    yOffset = 0;
-	CharSequence title = getTitle();
-	historyStack.add(new ViewHistory(adapter, selPosition, yOffset,
-					 title));
+	dispHistory.add(new DisplayAndPosition(curDisp, selPosition, yOffset));
     }
 
-    protected void saveView() {
-	final ListView lv = getListView();
+    protected void saveDisplay() {
 	lv.clearTextFilter();
-	final UnicodeArrayAdapter adapter
-	    = (UnicodeArrayAdapter) lv.getAdapter();
 	int position = lv.getSelectedItemPosition();
 	int position0 = lv.getFirstVisiblePosition();
 	if ( position == AdapterView.INVALID_POSITION )
@@ -105,9 +133,54 @@ public final class UnicodeMapActivity extends ListActivity {
 	    yOffset = view.getTop();
 	else
 	    yOffset = 0;
-	CharSequence title = getTitle();
-	historyStack.add(new ViewHistory(adapter, position, yOffset,
-					 title));
+	dispHistory.add(new DisplayAndPosition(curDisp, position, yOffset));
+    }
+
+    protected void doDisplay(Display disp) {
+	curDisp = disp;
+	List<UnicodeDisplayable> list;
+	UnicodeArrayAdapter adapter;
+	if ( disp instanceof RootDisplay ) {
+	    list = new ArrayList<UnicodeDisplayable>(UnicodeCharacter.Range.values().length);
+	    for ( UnicodeCharacter.Range rng : UnicodeCharacter.Range.values() )
+		list.add(rng);
+	    adapter = new UnicodeArrayAdapter(this, list);
+	    setListAdapter(adapter);
+	} else if ( disp instanceof RangeDisplay ) {
+	    int from = ((RangeDisplay)disp).getFrom();
+	    int to = ((RangeDisplay)disp).getTo();
+	    list = new ArrayList<UnicodeDisplayable>(db.countRange(from,to));
+	    for ( UnicodeCharacter ch : db.getRange(from,to) )
+		list.add(ch);
+	    adapter = new UnicodeArrayAdapter(this, list);
+	    setListAdapter(adapter);
+	} else if ( disp instanceof SearchDisplay ) {
+	    String s = ((SearchDisplay)disp).getLike();
+	    int limit = ((SearchDisplay)disp).getLimit();
+	    int sizeHint = ((SearchDisplay)disp).getSizeHint();
+	    list = new ArrayList<UnicodeDisplayable>(sizeHint);
+	    for ( UnicodeCharacter ch : db.searchNames(s,limit+1) )
+		list.add(ch);
+	    int size = list.size();
+	    ((SearchDisplay)disp).setSizeHint(size);
+	    boolean overflowed = ( size > limit );
+	    if ( overflowed )
+		list.remove(list.size()-1);
+	    adapter = new UnicodeArrayAdapter(this, list);
+	    setListAdapter(adapter);
+	    if ( overflowed ) {
+		String str = getResources().getString(R.string.list_too_long);
+		Toast.makeText(UnicodeMapActivity.this,
+			       String.format(str, limit),
+			       Toast.LENGTH_SHORT).show();
+	    }
+	} else
+	    throw new AssertionError("unknown UnicodeMapActivity.Display");
+	String title = disp.getTitle();
+	if ( title != null )
+	    setTitle(String.format(getResources().getString(R.string.app_name_spec), title));
+	else
+	    setTitle(getResources().getString(R.string.app_name));
     }
 
     protected class MapItemClickListener
@@ -120,20 +193,9 @@ public final class UnicodeMapActivity extends ListActivity {
 	    if ( it instanceof UnicodeCharacter )
 		textForm.append(((UnicodeCharacter)it).getChar());
 	    else if ( it instanceof UnicodeCharacter.Range ) {
-		int from = ((UnicodeCharacter.Range)it).getFrom();
-		int to = ((UnicodeCharacter.Range)it).getTo();
-		List<UnicodeDisplayable> list
-		    = new ArrayList<UnicodeDisplayable>(db.countRange(from,to));
-		for ( UnicodeCharacter ch : db.getRange(from,to) )
-		    list.add(ch);
-		UnicodeArrayAdapter adapter
-		    = new UnicodeArrayAdapter(UnicodeMapActivity.this,
-					      list);
-		saveView(view, position);
-		setListAdapter(adapter);
-		setTitle(String.format(getResources()
-				       .getString(R.string.app_name_spec),
-				       ((UnicodeCharacter.Range)it).getDescr()));
+		Display newDisp = new RangeDisplay((UnicodeCharacter.Range)it);
+		saveDisplay(view, position);
+		doDisplay(newDisp);
 	    } else
 		throw new AssertionError("unknown UnicodeDisplayable");
 	}
@@ -200,13 +262,7 @@ public final class UnicodeMapActivity extends ListActivity {
 	final boolean needPopulate = db.needPopulate();
 	if ( needPopulate )
 	    launchPopulation();
-	List<UnicodeDisplayable> rootList
-	    = new ArrayList<UnicodeDisplayable>(UnicodeCharacter.Range.values().length);
-	for ( UnicodeCharacter.Range rng : UnicodeCharacter.Range.values() )
-	    rootList.add(rng);
-	UnicodeArrayAdapter rootAdapter
-	    = new UnicodeArrayAdapter(this, rootList);
-	setListAdapter(rootAdapter);
+	doDisplay(new RootDisplay());
 	final ClipboardManager cmgr
 	    = (ClipboardManager)getSystemService(Context.CLIPBOARD_SERVICE);
 	final Button btn = (Button) findViewById(R.id.copyButton);
@@ -219,7 +275,7 @@ public final class UnicodeMapActivity extends ListActivity {
 				   Toast.LENGTH_SHORT).show();
 		}
 	    });
-	final ListView lv = getListView();
+	lv = getListView();
 	lv.setTextFilterEnabled(true);
 	MapItemClickListener listener = new MapItemClickListener();
 	lv.setOnItemClickListener(listener);
@@ -229,29 +285,10 @@ public final class UnicodeMapActivity extends ListActivity {
     final static int searchLimit = 1000;
 
     protected void doSearch(String s) {
-	List<UnicodeDisplayable> list
-	    = new ArrayList<UnicodeDisplayable>(128);
-	for ( UnicodeCharacter ch : db.searchNames(s,searchLimit+1) )
-	    list.add(ch);
-	boolean overflowed = ( list.size() > searchLimit );
-	if ( overflowed )
-	    list.remove(list.size()-1);
-	UnicodeArrayAdapter adapter
-	    = new UnicodeArrayAdapter(UnicodeMapActivity.this,
-				      list);
-	saveView();
-	setListAdapter(adapter);
-	setTitle(String.format(getResources()
-			       .getString(R.string.app_name_spec),
-			       getResources()
-			       .getString(R.string.search_results)));
-	if ( overflowed ) {
-	    String str = getResources().getString(R.string.list_too_long);
-	    android.util.Log.e("UnicodeMapActivity", "format is: "+str);
-	    Toast.makeText(UnicodeMapActivity.this,
-			   String.format(str, searchLimit),
-			   Toast.LENGTH_SHORT).show();
-	}
+	Display newDisp = new SearchDisplay(getResources().getString(R.string.search_results),
+					    s, searchLimit);
+	saveDisplay();
+	doDisplay(newDisp);
     }
 
     protected void querySearch() {
@@ -308,13 +345,10 @@ public final class UnicodeMapActivity extends ListActivity {
 
     @Override
     public boolean onKeyDown(int keyCode, KeyEvent event) {
-	if ( ( keyCode == KeyEvent.KEYCODE_BACK )
-	     && historyStack.size() > 0 ) {
-	    final ListView lv = getListView();
-	    ViewHistory saved = historyStack.remove(historyStack.size()-1);
-	    setListAdapter(saved.adapter);
-	    setTitle(saved.title);
-	    lv.setSelectionFromTop(saved.selPosition, saved.yOffset);
+	if ( ( keyCode == KeyEvent.KEYCODE_BACK ) && dispHistory.size() > 0 ) {
+	    DisplayAndPosition saved = dispHistory.remove(dispHistory.size()-1);
+	    doDisplay(saved.getDisp());
+	    lv.setSelectionFromTop(saved.getSelPosition(), saved.getYOffset());
 	    return true;
 	} else if ( keyCode == KeyEvent.KEYCODE_SEARCH ) {
 	    querySearch();