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.

1 files changed, 8 insertions, 6 deletions

diff --git a/src/qt/clientmodel.h b/src/qt/clientmodel.h
index 67835db727..bf2cd84a1c 100644
--- a/src/qt/clientmodel.h
+++ b/src/qt/clientmodel.h
@@ -10,6 +10,7 @@ class CWallet;
 
 QT_BEGIN_NAMESPACE
 class QDateTime;
+class QTimer;
 QT_END_NAMESPACE
 
 /** Model for Bitcoin network client. */
@@ -44,23 +45,24 @@ public:
 private:
     OptionsModel *optionsModel;
 
-    int cachedNumConnections;
     int cachedNumBlocks;
-    QString cachedStatusBar;
+    int cachedNumBlocksOfPeers;
 
     int numBlocksAtStartup;
 
+    QTimer *pollTimer;
+
 signals:
     void numConnectionsChanged(int count);
-    void numBlocksChanged(int count);
+    void numBlocksChanged(int count, int countOfPeers);
 
     //! Asynchronous error notification
     void error(const QString &title, const QString &message, bool modal);
 
 public slots:
-
-private slots:
-    void update();
+    void updateTimer();
+    void updateNumConnections(int numConnections);
+    void updateAlert(const QString &hash, int status);
 };
 
 #endif // CLIENTMODEL_H