From eaf93ae9970f34ed2d69fbd8b66beddaa82d37f6 Mon Sep 17 00:00:00 2001
From: nicolasroard <nicolasroard@google.com>
Date: Sun, 21 Oct 2012 18:42:07 -0700
Subject: Fix the undo/redo/reset menu item state

bug:7357734

- enable/disable the undo/redo/reset menu item
depending on the history.

Change-Id: I633008bc9a99eef2e7289b290fc96120f09b3825
---
 .../gallery3d/filtershow/FilterShowActivity.java   |  5 ++
 .../gallery3d/filtershow/HistoryAdapter.java       | 58 ++++++++++++++++++++--
 2 files changed, 59 insertions(+), 4 deletions(-)

diff --git a/src/com/android/gallery3d/filtershow/FilterShowActivity.java b/src/com/android/gallery3d/filtershow/FilterShowActivity.java
index cac8aadd6..3d968867f 100644
--- a/src/com/android/gallery3d/filtershow/FilterShowActivity.java
+++ b/src/com/android/gallery3d/filtershow/FilterShowActivity.java
@@ -464,6 +464,11 @@ public class FilterShowActivity extends Activity implements OnItemClickListener,
                 .getActionProvider();
         mShareActionProvider.setShareIntent(getDefaultShareIntent());
         mShareActionProvider.setOnShareTargetSelectedListener(this);
+
+        MenuItem undoItem = menu.findItem(R.id.undoButton);
+        MenuItem redoItem = menu.findItem(R.id.redoButton);
+        MenuItem resetItem = menu.findItem(R.id.resetHistoryButton);
+        mImageShow.getHistory().setMenuItems(undoItem, redoItem, resetItem);
         return true;
     }
 
diff --git a/src/com/android/gallery3d/filtershow/HistoryAdapter.java b/src/com/android/gallery3d/filtershow/HistoryAdapter.java
index 475f44313..684c2fc46 100644
--- a/src/com/android/gallery3d/filtershow/HistoryAdapter.java
+++ b/src/com/android/gallery3d/filtershow/HistoryAdapter.java
@@ -3,6 +3,7 @@ package com.android.gallery3d.filtershow;
 
 import android.content.Context;
 import android.view.LayoutInflater;
+import android.view.MenuItem;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.ArrayAdapter;
@@ -17,16 +18,61 @@ import java.util.Vector;
 public class HistoryAdapter extends ArrayAdapter<ImagePreset> {
     private static final String LOGTAG = "HistoryAdapter";
     private int mCurrentPresetPosition = 0;
+    private MenuItem mUndoMenuItem = null;
+    private MenuItem mRedoMenuItem = null;
+    private MenuItem mResetMenuItem = null;
+
+    public HistoryAdapter(Context context, int resource, int textViewResourceId) {
+        super(context, resource, textViewResourceId);
+        FilterShowActivity activity = (FilterShowActivity) context;
+    }
+
+    public void setMenuItems(MenuItem undoItem, MenuItem redoItem, MenuItem resetItem) {
+        mUndoMenuItem = undoItem;
+        mRedoMenuItem = redoItem;
+        mResetMenuItem = resetItem;
+        updateMenuItems();
+    }
+
+    public boolean canReset() {
+        if (getCount() <= 1) {
+            return false;
+        }
+        return true;
+    }
+
+    public boolean canUndo() {
+        if (mCurrentPresetPosition == getCount() - 1) {
+            return false;
+        }
+        return true;
+    }
+
+    public boolean canRedo() {
+        if (mCurrentPresetPosition == 0) {
+            return false;
+        }
+        return true;
+    }
+
+    public void updateMenuItems() {
+        if (mUndoMenuItem != null) {
+            mUndoMenuItem.setEnabled(canUndo());
+        }
+        if (mRedoMenuItem != null) {
+            mRedoMenuItem.setEnabled(canRedo());
+        }
+        if (mResetMenuItem != null) {
+            mResetMenuItem.setEnabled(canReset());
+        }
+    }
 
     public void setCurrentPreset(int n) {
         mCurrentPresetPosition = n;
+        updateMenuItems();
         this.notifyDataSetChanged();
     }
 
-    public HistoryAdapter(Context context, int resource, int textViewResourceId) {
-        super(context, resource, textViewResourceId);
-    }
-
     public void reset() {
         if (getCount() == 0) {
             return;
@@ -34,6 +80,7 @@ public class HistoryAdapter extends ArrayAdapter<ImagePreset> {
         ImagePreset first = getItem(getCount() - 1);
         clear();
         addHistoryItem(first);
+        updateMenuItems();
     }
 
     public ImagePreset getLast() {
@@ -46,6 +93,7 @@ public class HistoryAdapter extends ArrayAdapter<ImagePreset> {
     public void addHistoryItem(ImagePreset preset) {
         if (canAddHistoryItem(preset)) {
             insert(preset, 0);
+            updateMenuItems();
         }
     }
 
@@ -89,6 +137,7 @@ public class HistoryAdapter extends ArrayAdapter<ImagePreset> {
             mCurrentPresetPosition = 0;
         }
         this.notifyDataSetChanged();
+        updateMenuItems();
         return mCurrentPresetPosition;
     }
 
@@ -98,6 +147,7 @@ public class HistoryAdapter extends ArrayAdapter<ImagePreset> {
             mCurrentPresetPosition = getCount() - 1;
         }
         this.notifyDataSetChanged();
+        updateMenuItems();
         return mCurrentPresetPosition;
     }
 
-- 
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