Add cancel button to rescan progress dialog

Adds a cancel button to the rescan progress dialog. When it is clicked,
AbortRescan is called to abort a rescan

src/interfaces/wallet.cpp

@@ -132,6 +132,7 @@ public:
     {
         return m_wallet.ChangeWalletPassphrase(old_wallet_passphrase, new_wallet_passphrase);
     }
+    void abortRescan() override { m_wallet.AbortRescan(); }
     bool backupWallet(const std::string& filename) override { return m_wallet.BackupWallet(filename); }
     std::string getWalletName() override { return m_wallet.GetName(); }
     bool getKeyFromPool(bool internal, CPubKey& pub_key) override

src/interfaces/wallet.h

@@ -65,6 +65,9 @@ public:
     virtual bool changeWalletPassphrase(const SecureString& old_wallet_passphrase,
         const SecureString& new_wallet_passphrase) = 0;
 
+    //! Abort a rescan.
+    virtual void abortRescan() = 0;
+
     //! Back up wallet.
     virtual bool backupWallet(const std::string& filename) = 0;
 

src/qt/walletview.cpp

@@ -315,9 +315,9 @@ void WalletView::showProgress(const QString &title, int nProgress)
         progressDialog = new QProgressDialog(title, "", 0, 100);
         progressDialog->setWindowModality(Qt::ApplicationModal);
         progressDialog->setMinimumDuration(0);
-        progressDialog->setCancelButton(0);
         progressDialog->setAutoClose(false);
         progressDialog->setValue(0);
+        progressDialog->setCancelButtonText(tr("Cancel"));
     }
     else if (nProgress == 100)
     {
@@ -327,8 +327,13 @@ void WalletView::showProgress(const QString &title, int nProgress)
             progressDialog->deleteLater();
         }
     }
-    else if (progressDialog)
-        progressDialog->setValue(nProgress);
+    else if (progressDialog) {
+        if (progressDialog->wasCanceled()) {
+            getWalletModel()->wallet().abortRescan();
+        } else {
+            progressDialog->setValue(nProgress);
+        }
+    }
 }
 
 void WalletView::requestedSyncWarningInfo()

src/wallet/rpcdump.cpp

@@ -534,9 +534,11 @@ UniValue importwallet(const JSONRPCRequest& request)
         int64_t nFilesize = std::max((int64_t)1, (int64_t)file.tellg());
         file.seekg(0, file.beg);
 
-        pwallet->ShowProgress(_("Importing..."), 0); // show progress dialog in GUI
+        // Use uiInterface.ShowProgress instead of pwallet.ShowProgress because pwallet.ShowProgress has a cancel button tied to AbortRescan which
+        // we don't want for this progress bar shoing the import progress. uiInterface.ShowProgress does not have a cancel button.
+        uiInterface.ShowProgress(_("Importing..."), 0, false); // show progress dialog in GUI
         while (file.good()) {
-            pwallet->ShowProgress("", std::max(1, std::min(99, (int)(((double)file.tellg() / (double)nFilesize) * 100))));
+            uiInterface.ShowProgress("", std::max(1, std::min(99, (int)(((double)file.tellg() / (double)nFilesize) * 100))), false);
             std::string line;
             std::getline(file, line);
             if (line.empty() || line[0] == '#')
@@ -599,7 +601,7 @@ UniValue importwallet(const JSONRPCRequest& request)
             }
         }
         file.close();
-        pwallet->ShowProgress("", 100); // hide progress dialog in GUI
+        uiInterface.ShowProgress("", 100, false); // hide progress dialog in GUI
         pwallet->UpdateTimeFirstKey(nTimeBegin);
     }
     pwallet->RescanFromTime(nTimeBegin, reserver, false /* update */);