Merge bitcoin-core/gui#214: qt: Disable requests context menu actions when appropriate

bb3da8fe410285887f22679c6f08a1f40bcfac8f qt: Disable requests context menu actions when appropriate (Jarol Rodriguez)

Pull request description:

  The recent requests table will allow you to copy data points even if they do not exist. This PR implements checks to disable the `copy label`, `copy message`, and `copy amount` context menu actions if the respective fields are empty. This brings the recent requests table context menu behavior closer to the behavior seen in the transaction view.

  On a payment request entry which does not have a value for label, message, or amount:
  | Master        | PR               |
  | ----------- | ----------- |
  |<img width="169" alt="Screen Shot 2021-02-19 at 1 22 28 AM" src="https://user-images.githubusercontent.com/23396902/108466086-167adc00-7251-11eb-8bd6-13984042bdb3.png">| <img width="169" alt="Screen Shot 2021-02-19 at 1 21 49 AM" src="https://user-images.githubusercontent.com/23396902/108466185-3e6a3f80-7251-11eb-9dd8-492ed07fd638.png">|

  `copy URI` never needs to be disabled as an entry in the recent requests table must have a URI even if it doesn't have a label, message, or amount. #213 will add a `copy address` context menu action. This also does not need a check as an entry must be associated with an address.

  Below are some more examples of how this PR will behave:
  **Has Label, Message, and Amount**
  <img width="780" alt="Screen Shot 2021-02-19 at 12 05 38 AM" src="https://user-images.githubusercontent.com/23396902/108466507-c18b9580-7251-11eb-8875-f3aeb9c4c8e9.png">

  **Has Label and Amount, but no Message**
  <img width="780" alt="Screen Shot 2021-02-19 at 12 05 58 AM" src="https://user-images.githubusercontent.com/23396902/108466421-9b65f580-7251-11eb-97eb-a3bfaa21fa7d.png">

ACKs for top commit:
  hebasto:
    re-ACK bb3da8fe410285887f22679c6f08a1f40bcfac8f

Tree-SHA512: d98f1a6e05ebf6d9d056bc5754aca78ca7ecda93f497dba88187b947ca4a261eb7dc5e8c872956315acaa0008cc39320fb5806e17117e0c873090ad917ca4a3d

2 files changed, 16 insertions, 4 deletions

diff --git a/src/qt/receivecoinsdialog.cpp b/src/qt/receivecoinsdialog.cpp
index 62adaa4e9f..0da12c84fd 100644
--- a/src/qt/receivecoinsdialog.cpp
+++ b/src/qt/receivecoinsdialog.cpp
@@ -45,9 +45,9 @@ ReceiveCoinsDialog::ReceiveCoinsDialog(const PlatformStyle *_platformStyle, QWid
     // context menu actions
     QAction *copyURIAction = new QAction(tr("Copy URI"), this);
     QAction* copyAddressAction = new QAction(tr("Copy address"), this);
-    QAction *copyLabelAction = new QAction(tr("Copy label"), this);
-    QAction *copyMessageAction = new QAction(tr("Copy message"), this);
-    QAction *copyAmountAction = new QAction(tr("Copy amount"), this);
+    copyLabelAction = new QAction(tr("Copy label"), this);
+    copyMessageAction = new QAction(tr("Copy message"), this);
+    copyAmountAction = new QAction(tr("Copy amount"), this);
 
     // context menu
     contextMenu = new QMenu(this);
@@ -269,9 +269,18 @@ void ReceiveCoinsDialog::copyColumnToClipboard(int column)
 // context menu
 void ReceiveCoinsDialog::showMenu(const QPoint &point)
 {
-    if (!selectedRow().isValid()) {
+    const QModelIndex sel = selectedRow();
+    if (!sel.isValid()) {
         return;
     }
+
+    // disable context menu actions when appropriate
+    const RecentRequestsTableModel* const submodel = model->getRecentRequestsTableModel();
+    const RecentRequestEntry& req = submodel->entry(sel.row());
+    copyLabelAction->setDisabled(req.recipient.label.isEmpty());
+    copyMessageAction->setDisabled(req.recipient.message.isEmpty());
+    copyAmountAction->setDisabled(req.recipient.amount == 0);
+
     contextMenu->exec(QCursor::pos());
 }
 
diff --git a/src/qt/receivecoinsdialog.h b/src/qt/receivecoinsdialog.h
index f12cd8ce0c..fbbccc5a33 100644
--- a/src/qt/receivecoinsdialog.h
+++ b/src/qt/receivecoinsdialog.h
@@ -53,6 +53,9 @@ private:
     Ui::ReceiveCoinsDialog *ui;
     WalletModel *model;
     QMenu *contextMenu;
+    QAction* copyLabelAction;
+    QAction* copyMessageAction;
+    QAction* copyAmountAction;
     const PlatformStyle *platformStyle;
 
     QModelIndex selectedRow();