WinMerge · sdottaka · Jun 11, 2023 · Jun 11, 2023
diff --git a/Src/Merge.rc b/Src/Merge.rc
@@ -1661,16 +1661,17 @@ CAPTION "Go to"
 FONT 8, "MS Shell Dlg", 0, 0, 0x1
 BEGIN
     LTEXT           "G&o to:",IDC_STATIC,7,9,68,10
-    EDITTEXT        IDC_WMGOTO_PARAM,77,7,78,14,ES_AUTOHSCROLL | ES_NUMBER
+    LTEXT           "", IDC_WMGOTO_RANGE,77,9,65,10
+    EDITTEXT        IDC_WMGOTO_PARAM,146,7,64,14,ES_AUTOHSCROLL | ES_NUMBER
     GROUPBOX        "File",IDC_STATIC,7,27,65,45
     CONTROL         "&Left",IDC_WMGOTO_FILELEFT,"Button",BS_AUTORADIOBUTTON | WS_GROUP,13,38,56,10
     CONTROL         "&Middle",IDC_WMGOTO_FILEMIDDLE,"Button",BS_AUTORADIOBUTTON,13,48,56,10
     CONTROL         "&Right",IDC_WMGOTO_FILERIGHT,"Button",BS_AUTORADIOBUTTON,13,58,56,10
     GROUPBOX        "Go to what",IDC_STATIC,77,27,78,45
     CONTROL         "Li&ne",IDC_WMGOTO_TOLINE,"Button",BS_AUTORADIOBUTTON | WS_GROUP,84,38,68,10
     CONTROL         "&Difference",IDC_WMGOTO_TODIFF,"Button",BS_AUTORADIOBUTTON,84,48,68,10
-    DEFPUSHBUTTON   "&Go to",IDOK,161,7,50,14
-    PUSHBUTTON      "Cancel",IDCANCEL,161,24,50,14
+    DEFPUSHBUTTON   "&Go to",IDOK,161,41,50,14
+    PUSHBUTTON      "Cancel",IDCANCEL,161,58,50,14
 END
 
 IDD_PROPPAGE_COMPARE DIALOGEX 0, 0, 285, 242

diff --git a/Src/MergeEditView.cpp b/Src/MergeEditView.cpp
@@ -3047,6 +3047,10 @@ void CMergeEditView::OnWMGoto()
 	dlg.m_nFile = (pDoc->m_nBuffers < 3) ? (m_nThisPane == 1 ? 2 : 0) : m_nThisPane;
 	dlg.m_nGotoWhat = 0;
 	dlg.m_nFiles = pDoc->m_nBuffers;
+	dlg.m_nLastLine[0] = nLastLine[0] + 1;
+	dlg.m_nLastLine[1] = (pDoc->m_nBuffers < 3) ? -1 : nLastLine[1] + 1;
+	dlg.m_nLastLine[2] = (pDoc->m_nBuffers < 3) ? nLastLine[1] + 1: nLastLine[2] + 1;
+	dlg.m_nLastDiff = pDoc->m_diffList.GetSize();
 
 	if (dlg.DoModal() == IDOK)
 	{

diff --git a/Src/WMGotoDlg.cpp b/Src/WMGotoDlg.cpp
@@ -45,11 +45,18 @@ class WMGotoDlg::Impl : public CTrDialog
 	// Generated message map functions
 	//{{AFX_MSG(WMGotoDlg)
 		// NOTE: the ClassWizard will add member functions here
+	afx_msg void OnChangeParam();
+	afx_msg void OnBnClicked(UINT nID);
 	//}}AFX_MSG
 	DECLARE_MESSAGE_MAP()
 
 private:
 	WMGotoDlg *m_p;
+	String m_strRange;			/**< Acceptable range */
+
+	int GetRangeMax();
+	void UpdateRange();
+	void UpdateGoToButton();
 };
 
 /////////////////////////////////////////////////////////////////////////////
@@ -74,6 +81,12 @@ BOOL WMGotoDlg::Impl::OnInitDialog()
 
 	if (m_p->m_nFiles < 3)
 		EnableDlgItem(IDC_WMGOTO_FILEMIDDLE, false);
+	if (m_p->m_nLastDiff == 0)
+		EnableDlgItem(IDC_WMGOTO_TODIFF, false);
+
+	UpdateRange();
+	UpdateGoToButton();
+	UpdateData(FALSE);
 
 	return TRUE;
 }
@@ -85,23 +98,95 @@ void WMGotoDlg::Impl::DoDataExchange(CDataExchange* pDX)
 	DDX_Text(pDX, IDC_WMGOTO_PARAM, m_p->m_strParam);
 	DDX_Radio(pDX, IDC_WMGOTO_FILELEFT, m_p->m_nFile);
 	DDX_Radio(pDX, IDC_WMGOTO_TOLINE, m_p->m_nGotoWhat);
+	DDX_Text(pDX, IDC_WMGOTO_RANGE, m_strRange);
 	//}}AFX_DATA_MAP
 }
 
 
 BEGIN_MESSAGE_MAP(WMGotoDlg::Impl, CTrDialog)
 	//{{AFX_MSG_MAP(WMGotoDlg::Impl)
 		// NOTE: the ClassWizard will add message map macros here
+	ON_EN_CHANGE(IDC_WMGOTO_PARAM, OnChangeParam)
+	ON_CONTROL_RANGE(BN_CLICKED, IDC_WMGOTO_FILELEFT, IDC_WMGOTO_FILERIGHT, OnBnClicked)
+	ON_CONTROL_RANGE(BN_CLICKED, IDC_WMGOTO_TOLINE, IDC_WMGOTO_TODIFF, OnBnClicked)
 	//}}AFX_MSG_MAP
 END_MESSAGE_MAP()
 
+/**
+ * @brief Called when the edit string changes.
+ */
+void WMGotoDlg::Impl::OnChangeParam()
+{
+	UpdateData(TRUE);
+	UpdateGoToButton();
+}
+
+/**
+ * @brief Called when user selects "File" or "Go to what" radio button.
+ * @param [in] nID Button ID of the selected item
+ */
+void WMGotoDlg::Impl::OnBnClicked(UINT nID)
+{
+	bool bIsValidId = (nID >= IDC_WMGOTO_FILELEFT && nID <= IDC_WMGOTO_FILERIGHT) || (nID >= IDC_WMGOTO_TOLINE && nID <= IDC_WMGOTO_TODIFF);
+	assert(bIsValidId);
+	if (!bIsValidId)
+		return;
+
+	UpdateData(TRUE);
+	UpdateRange();
+	UpdateGoToButton();
+	UpdateData(FALSE);
+}
+
+/**
+ * @brief Get upper bound of acceptable range for selected "File" and "Go to what".
+ * @return Upper bound of acceptable range for selected "File" and "Go to what".
+ */
+int WMGotoDlg::Impl::GetRangeMax()
+{
+	bool bIsValidState = ((m_p->m_nGotoWhat >= 0 && m_p->m_nGotoWhat <= 1) && (m_p->m_nFile >= 0 && m_p->m_nFile <= 2));
+	assert(bIsValidState);
+	if (!bIsValidState)
+		return -1;
+
+	return (m_p->m_nGotoWhat == 0) ? m_p->m_nLastLine[m_p->m_nFile] : m_p->m_nLastDiff;
+}
+
+/**
+ * @brief Update the acceptable range.
+ */
+void WMGotoDlg::Impl::UpdateRange()
+{
+	int nRangeMax = GetRangeMax();
+	m_strRange = (nRangeMax > 0) ? strutils::format(_T("(1-%d)"), nRangeMax) : _T("");
+}
+
+/**
+ * @brief Update the enabled state of the "Go to" button.
+ */
+void WMGotoDlg::Impl::UpdateGoToButton()
+{
+	int nNum = 0;
+	try
+	{
+		nNum = std::stoi(m_p->m_strParam);
+	}
+	catch (...)
+	{
+		nNum = 0;
+	}
+
+	bool bEnable = (nNum > 0 && nNum <= GetRangeMax());
+	EnableDlgItem(IDOK, bEnable);
+}
+
 /////////////////////////////////////////////////////////////////////////////
 // WMGotoDlg message handlers
 
 
 
 WMGotoDlg::WMGotoDlg()
-	: m_pimpl(new WMGotoDlg::Impl(this)), m_nFile(-1), m_nGotoWhat(-1), m_nFiles(-1) {}
+	: m_pimpl(new WMGotoDlg::Impl(this)), m_nFile(-1), m_nGotoWhat(-1), m_nFiles(-1), m_nLastLine{-1, -1, -1}, m_nLastDiff(-1) {}
 WMGotoDlg::~WMGotoDlg() = default;
 int WMGotoDlg::DoModal() { return static_cast<int>(m_pimpl->DoModal()); }
 
diff --git a/Src/WMGotoDlg.h b/Src/WMGotoDlg.h
@@ -22,6 +22,8 @@ class WMGotoDlg
 	int m_nFile;         /**< Target file number. */
 	int m_nGotoWhat;     /**< Goto line or difference? */
 	int m_nFiles;        /**< Number of files being compared. */
+	int m_nLastLine[3];  /**< Last line in each pane. */
+	int m_nLastDiff;     /**< Last diff. */
 private:
 	WMGotoDlg(const WMGotoDlg &) = delete;
 	WMGotoDlg & operator=(const WMGotoDlg &) = delete;

diff --git a/Src/resource.h b/Src/resource.h
@@ -301,13 +301,14 @@
 #define IDC_WMGOTO_TOLINE               1115
 #define IDC_WMGOTO_TODIFF               1116
 #define IDC_WMGOTO_PARAM                1117
-#define IDC_OPEN_CONTRIBUTORS           1118
-#define IDC_COMPAREMETHODCOMBO          1119
-#define IDC_USE_RECYCLE_BIN             1120
-#define IDC_COMPARE_DEFAULTS            1121
-#define IDC_DIFF_DEFAULTS               1122
-#define IDC_MOVED_BLOCKS                1123
-#define IDC_RESET_ALL_MESSAGE_BOXES     1124
+#define IDC_WMGOTO_RANGE                1118
+#define IDC_OPEN_CONTRIBUTORS           1119
+#define IDC_COMPAREMETHODCOMBO          1120
+#define IDC_USE_RECYCLE_BIN             1121
+#define IDC_COMPARE_DEFAULTS            1122
+#define IDC_DIFF_DEFAULTS               1123
+#define IDC_MOVED_BLOCKS                1124
+#define IDC_RESET_ALL_MESSAGE_BOXES     1125
 #define IDC_COLDLG_DEFAULTS             1126
 #define IDC_COLDLG_ADDITIONAL_PROPERTIES 1127
 #define IDC_OPEN_STATUS                 1128