Fine-grained UI updates

Gets rid of `MainFrameRepaint` in favor of specific update functions that tell the UI exactly what changed.

This improves the efficiency of various handlers. Also fixes problems with mined transactions not showing up until restart.

The following notifications were added:

- `NotifyBlocksChanged`: Block chain changed
- `NotifyKeyStoreStatusChanged`: Wallet status (encrypted, locked) changed.
- `NotifyAddressBookChanged`: Address book entry changed.
- `NotifyTransactionChanged`: Wallet transaction added, removed or updated.
- `NotifyNumConnectionsChanged`: Number of connections changed.
- `NotifyAlertChanged`: New, updated or cancelled alert. As this finally makes it possible for the UI to know when a new alert arrived, it can be shown as OS notification.

These notifications could also be useful for RPC clients. However, currently, they are ignored in bitcoind (in noui.cpp).

Also brings back polling with timer for numBlocks in ClientModel. This value updates so frequently during initial download that the number of signals clogs the UI thread and causes heavy CPU usage. And after initial block download, the value changes so rarely that a delay of half a second until the UI updates is unnoticable.

src/wallet.cpp

@@ -274,7 +274,9 @@ bool CWallet::EncryptWallet(const SecureString& strWalletPassphrase)
         // Need to completely rewrite the wallet file; if we don't, bdb might keep
         // bits of the unencrypted private key in slack space in the database file.
         CDB::Rewrite(strWalletFile);
+
     }
+    NotifyKeyStoreStatusChanged(this);
 
     return true;
 }
@@ -297,7 +299,7 @@ void CWallet::WalletUpdateSpent(const CTransaction &tx)
                     printf("WalletUpdateSpent found spent coin %sbc %s\n", FormatMoney(wtx.GetCredit()).c_str(), wtx.GetHash().ToString().c_str());
                     wtx.MarkSpent(txin.prevout.n);
                     wtx.WriteToDisk();
-                    vWalletUpdated.push_back(txin.prevout.hash);
+                    NotifyTransactionChanged(this, txin.prevout.hash, CT_UPDATED);
                 }
             }
         }
@@ -373,15 +375,12 @@ bool CWallet::AddToWallet(const CWalletTx& wtxIn)
             }
         }
 #endif
-        // Notify UI
-        vWalletUpdated.push_back(hash);
-
         // since AddToWallet is called directly for self-originating transactions, check for consumption of own coins
         WalletUpdateSpent(wtx);
-    }
 
-    // Refresh UI
-    MainFrameRepaint();
+        // Notify UI of new or updated transaction
+        NotifyTransactionChanged(this, hash, fInsertedNew ? CT_NEW : CT_UPDATED);
+    }
     return true;
 }
 
@@ -1183,7 +1182,7 @@ bool CWallet::CommitTransaction(CWalletTx& wtxNew, CReserveKey& reservekey)
                 coin.BindWallet(this);
                 coin.MarkSpent(txin.prevout.n);
                 coin.WriteToDisk();
-                vWalletUpdated.push_back(coin.GetHash());
+                NotifyTransactionChanged(this, coin.GetHash(), CT_UPDATED);
             }
 
             if (fFileBacked)
@@ -1202,7 +1201,6 @@ bool CWallet::CommitTransaction(CWalletTx& wtxNew, CReserveKey& reservekey)
         }
         wtxNew.RelayWalletTransaction();
     }
-    MainFrameRepaint();
     return true;
 }
 
@@ -1237,7 +1235,6 @@ string CWallet::SendMoney(CScript scriptPubKey, int64 nValue, CWalletTx& wtxNew,
     if (!CommitTransaction(wtxNew, reservekey))
         return _("Error: The transaction was rejected.  This might happen if some of the coins in your wallet were already spent, such as if you used a copy of wallet.dat and coins were spent in the copy but not marked as spent here.");
 
-    MainFrameRepaint();
     return "";
 }
 
@@ -1290,8 +1287,9 @@ int CWallet::LoadWallet(bool& fFirstRunRet)
 
 bool CWallet::SetAddressBookName(const CBitcoinAddress& address, const string& strName)
 {
+    std::map<CBitcoinAddress, std::string>::iterator mi = mapAddressBook.find(address);
     mapAddressBook[address] = strName;
-    AddressBookRepaint();
+    NotifyAddressBookChanged(this, address.ToString(), strName, (mi == mapAddressBook.end()) ? CT_NEW : CT_UPDATED);
     if (!fFileBacked)
         return false;
     return CWalletDB(strWalletFile).WriteName(address.ToString(), strName);
@@ -1300,7 +1298,7 @@ bool CWallet::SetAddressBookName(const CBitcoinAddress& address, const string& s
 bool CWallet::DelAddressBookName(const CBitcoinAddress& address)
 {
     mapAddressBook.erase(address);
-    AddressBookRepaint();
+    NotifyAddressBookChanged(this, address.ToString(), "", CT_DELETED);
     if (!fFileBacked)
         return false;
     return CWalletDB(strWalletFile).EraseName(address.ToString());
@@ -1558,3 +1556,14 @@ void CWallet::GetAllReserveAddresses(set<CBitcoinAddress>& setAddress)
         setAddress.insert(address);
     }
 }
+
+void CWallet::UpdatedTransaction(const uint256 &hashTx)
+{
+    {
+        LOCK(cs_wallet);
+        // Only notify UI if this transaction is in this wallet
+        map<uint256, CWalletTx>::const_iterator mi = mapWallet.find(hashTx);
+        if (mi != mapWallet.end())
+            NotifyTransactionChanged(this, hashTx, CT_UPDATED);
+    }
+}