From b32a0aa0e7325848d6469c7d3b56fe7e9bde4a61 Mon Sep 17 00:00:00 2001
From: Christian Stimming <stimming@tuhh.de>
Date: Sat, 8 Oct 2011 20:30:28 +0000
Subject: [PATCH] Let the "assign payment" feature choose customer or vendor
 payment, depending on whether the amount is positive or negative.

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/trunk@21401 57a11ea4-9604-0410-9ed3-97b8803252fd
---
 src/business/business-gnome/dialog-payment.c  | 32 +++++++++++++++++++
 src/business/business-gnome/dialog-payment.h  |  4 +++
 .../business-gnome/gnc-plugin-business.c      |  6 +++-
 3 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/src/business/business-gnome/dialog-payment.c b/src/business/business-gnome/dialog-payment.c
index 1ba1bdea46..47df9836b7 100644
--- a/src/business/business-gnome/dialog-payment.c
+++ b/src/business/business-gnome/dialog-payment.c
@@ -826,6 +826,37 @@ static Split *getFirstOtherSplit(SplitList* slist, const Split *postaccount_spli
 
 // ///////////////
 
+gboolean gnc_ui_payment_is_customer_payment(const Transaction *txn)
+{
+    SplitList *slist;
+    gboolean result = TRUE;
+
+    if (!txn)
+        return result;
+
+    // We require the txn to have one split in an A/R or A/P account.
+
+    slist = xaccTransGetSplitList(txn);
+    if (!slist)
+        return result;
+    if (countAssetAccounts(slist) == 0)
+    {
+        g_message("No asset splits in txn \"%s\"; cannot use this for assigning a payment.",
+                  xaccTransGetDescription(txn));
+        return result;
+    }
+
+    {
+        Split *assetaccount_split = getFirstAssetAccountSplit(slist);
+        gnc_numeric amount = xaccSplitGetValue(assetaccount_split);
+        gboolean result = gnc_numeric_positive_p(amount); // positive amounts == customer
+        //g_message("Amount=%s", gnc_numeric_to_string(amount));
+        return result;
+    }
+}
+
+// ///////////////
+
 PaymentWindow * gnc_ui_payment_new_with_txn (GncOwner *owner, Transaction *txn)
 {
     SplitList *slist;
@@ -853,6 +884,7 @@ PaymentWindow * gnc_ui_payment_new_with_txn (GncOwner *owner, Transaction *txn)
         PaymentWindow *pw = gnc_ui_payment_new(owner,
                                                qof_instance_get_book(QOF_INSTANCE(txn)));
         g_assert(assetaccount_split); // we can rely on this because of the countAssetAccounts() check above
+        //g_message("Amount=%s", gnc_numeric_to_string(amount));
 
         // Fill in the values from the given txn
         pw->pre_existing_txn = txn;
diff --git a/src/business/business-gnome/dialog-payment.h b/src/business/business-gnome/dialog-payment.h
index da0d6d7c4e..2f8fd42e97 100644
--- a/src/business/business-gnome/dialog-payment.h
+++ b/src/business/business-gnome/dialog-payment.h
@@ -36,6 +36,10 @@ PaymentWindow * gnc_ui_payment_new_with_invoice (GncOwner *owner,
         GncInvoice *invoice);
 PaymentWindow * gnc_ui_payment_new_with_txn (GncOwner *owner, Transaction *txn);
 
+/** Returns TRUE if the given transaction (to be used with gnc_ui_payment_new_with_txn() )
+ * is for a customer, or FALSE if it's from a vendor or employee voucher. */
+gboolean gnc_ui_payment_is_customer_payment(const Transaction *txn);
+
 /* Destroy a payment window */
 void gnc_ui_payment_window_destroy (PaymentWindow *pw);
 
diff --git a/src/business/business-gnome/gnc-plugin-business.c b/src/business/business-gnome/gnc-plugin-business.c
index 4cbc008f3b..cd8d3722e3 100644
--- a/src/business/business-gnome/gnc-plugin-business.c
+++ b/src/business/business-gnome/gnc-plugin-business.c
@@ -896,6 +896,7 @@ static void gnc_plugin_business_cmd_assign_payment (GtkAction *action,
     SplitRegister *reg;
     Split *split;
     Transaction *trans;
+    gboolean is_customer;
 
     g_return_if_fail (mw != NULL);
     g_return_if_fail (GNC_IS_PLUGIN_BUSINESS (mw->data));
@@ -919,13 +920,16 @@ static void gnc_plugin_business_cmd_assign_payment (GtkAction *action,
 
     trans = xaccSplitGetParent(split);
     g_return_if_fail(trans);
+    is_customer = gnc_ui_payment_is_customer_payment(trans);
 
     plugin_business = GNC_PLUGIN_BUSINESS (mw->data);
     plugin_business_priv = GNC_PLUGIN_BUSINESS_GET_PRIVATE (plugin_business);
 
     gnc_business_assign_payment (gnc_plugin_page_get_window(plugin_page),
                                  trans,
-                                 plugin_business_priv->last_customer);
+                                 is_customer
+                                 ? plugin_business_priv->last_customer
+                                 : plugin_business_priv->last_vendor);
 }
 
 static const gchar *register_txn_actions[] =