Add special case setV code for button fields

include/qpdf/QPDFFormFieldObjectHelper.hh

@@ -163,10 +163,13 @@ class QPDFFormFieldObjectHelper: public QPDFObjectHelper
     void setFieldAttribute(std::string const& key,
                            std::string const& utf8_value);
 
-    // Set /V (field value) to the given value. Optionally set
-    // /NeedAppearances to true. You can explicitly tell this method
-    // not to set /NeedAppearances if you are going to explicitly
-    // generate an appearance stream yourself.
+    // Set /V (field value) to the given value. If need_appearances is
+    // true and the field type is either /Tx (text) or /Ch (choice),
+    // set /NeedAppearances to true. You can explicitly tell this
+    // method not to set /NeedAppearances if you are going to generate
+    // an appearance stream yourself. Starting with qpdf 8.3.0, this
+    // method handles fields of type /Btn (checkboxes, radio buttons,
+    // pushbuttons) specially.
     QPDF_DLL
     void setV(QPDFObjectHandle value, bool need_appearances = true);
 
@@ -177,6 +180,9 @@ class QPDFFormFieldObjectHelper: public QPDFObjectHelper
     void setV(std::string const& utf8_value, bool need_appearances = true);
 
   private:
+    void setRadioButtonValue(QPDFObjectHandle name);
+    void setCheckBoxValue(bool value);
+
     class Members
     {
         friend class QPDFFormFieldObjectHelper;

libqpdf/QPDFFormFieldObjectHelper.cc

@@ -272,6 +272,47 @@ void
 QPDFFormFieldObjectHelper::setV(
     QPDFObjectHandle value, bool need_appearances)
 {
+    if (getFieldType() == "/Btn")
+    {
+        if (isCheckbox())
+        {
+            bool okay = false;
+            if (value.isName())
+            {
+                std::string name = value.getName();
+                if ((name == "/Yes") || (name == "/Off"))
+                {
+                    okay = true;
+                    setCheckBoxValue((name == "/Yes"));
+                }
+            }
+            if (! okay)
+            {
+                this->oh.warnIfPossible(
+                    "ignoring attempt to set a checkbox field to a"
+                    " value of other than /Yes or /Off");
+            }
+        }
+        else if (isRadioButton())
+        {
+            if (value.isName())
+            {
+                setRadioButtonValue(value);
+            }
+            else
+            {
+                this->oh.warnIfPossible(
+                    "ignoring attempt to set a radio button field to"
+                    " an object that is not a name");
+            }
+        }
+        else if (isPushbutton())
+        {
+            this->oh.warnIfPossible(
+                "ignoring attempt set the value of a pushbutton field");
+        }
+        return;
+    }
     setFieldAttribute("/V", value);
     if (need_appearances)
     {
@@ -294,3 +335,138 @@ QPDFFormFieldObjectHelper::setV(
     setV(QPDFObjectHandle::newUnicodeString(utf8_value),
          need_appearances);
 }
+
+void
+QPDFFormFieldObjectHelper::setRadioButtonValue(QPDFObjectHandle name)
+{
+    // Set the value of a radio button field. This has the following
+    // specific behavior:
+    // * If this is a radio button field that has a parent that is
+    //   also a radio button field and has no explicit /V, call itself
+    //   on the parent
+    // * If this is a radio button field with childen, set /V to the
+    //   given value. Then, for each child, if the child has the
+    //   specified value as one of its keys in the /N subdictionary of
+    //   its /AP (i.e. its normal appearance stream dictionary), set
+    //   /AS to name; otherwise, if /Off is a member, set /AS to /Off.
+    // Note that we never turn on /NeedAppearances when setting a
+    // radio button field.
+    QPDFObjectHandle parent = this->oh.getKey("/Parent");
+    if (parent.isDictionary() && parent.getKey("/Parent").isNull())
+    {
+        QPDFFormFieldObjectHelper ph(parent);
+        if (ph.isRadioButton())
+        {
+            // This is most likely one of the individual buttons. Try
+            // calling on the parent.
+            QTC::TC("qpdf", "QPDFFormFieldObjectHelper set parent radio button");
+            ph.setRadioButtonValue(name);
+            return;
+        }
+    }
+
+    QPDFObjectHandle kids = this->oh.getKey("/Kids");
+    if (! (isRadioButton() && parent.isNull() && kids.isArray()))
+    {
+        this->oh.warnIfPossible("don't know how to set the value"
+                                " of this field as a radio button");
+        return;
+    }
+    setFieldAttribute("/V", name);
+    int nkids = kids.getArrayNItems();
+    for (int i = 0; i < nkids; ++i)
+    {
+        QPDFObjectHandle kid = kids.getArrayItem(i);
+        QPDFObjectHandle AP = kid.getKey("/AP");
+        QPDFObjectHandle annot;
+        if (AP.isNull())
+        {
+            // The widget may be below. If there is more than one,
+            // just find the first one.
+            QPDFObjectHandle grandkids = kid.getKey("/Kids");
+            if (grandkids.isArray())
+            {
+                int ngrandkids = grandkids.getArrayNItems();
+                for (int j = 0; j < ngrandkids; ++j)
+                {
+                    QPDFObjectHandle grandkid = grandkids.getArrayItem(j);
+                    AP = grandkid.getKey("/AP");
+                    if (! AP.isNull())
+                    {
+                        QTC::TC("qpdf", "QPDFFormFieldObjectHelper radio button grandkid widget");
+                        annot = grandkid;
+                        break;
+                    }
+                }
+            }
+        }
+        else
+        {
+            annot = kid;
+        }
+        if (! annot.isInitialized())
+        {
+            QTC::TC("qpdf", "QPDFObjectHandle broken radio button");
+            this->oh.warnIfPossible(
+                "unable to set the value of this radio button");
+            continue;
+        }
+        if (AP.isDictionary() &&
+            AP.getKey("/N").isDictionary() &&
+            AP.getKey("/N").hasKey(name.getName()))
+        {
+            QTC::TC("qpdf", "QPDFFormFieldObjectHelper turn on radio button");
+            annot.replaceKey("/AS", name);
+        }
+        else
+        {
+            QTC::TC("qpdf", "QPDFFormFieldObjectHelper turn off radio button");
+            annot.replaceKey("/AS", QPDFObjectHandle::newName("/Off"));
+        }
+    }
+}
+
+void
+QPDFFormFieldObjectHelper::setCheckBoxValue(bool value)
+{
+    // Set /AS to /Yes or /Off in addition to setting /V.
+    QPDFObjectHandle name =
+        QPDFObjectHandle::newName(value ? "/Yes" : "/Off");
+    setFieldAttribute("/V", name);
+    QPDFObjectHandle AP = this->oh.getKey("/AP");
+    QPDFObjectHandle annot;
+    if (AP.isNull())
+    {
+        // The widget may be below. If there is more than one, just
+        // find the first one.
+        QPDFObjectHandle kids = this->oh.getKey("/Kids");
+        if (kids.isArray())
+        {
+            int nkids = kids.getArrayNItems();
+            for (int i = 0; i < nkids; ++i)
+            {
+                QPDFObjectHandle kid = kids.getArrayItem(i);
+                AP = kid.getKey("/AP");
+                if (! AP.isNull())
+                {
+                    QTC::TC("qpdf", "QPDFFormFieldObjectHelper checkbox kid widget");
+                    annot = kid;
+                    break;
+                }
+            }
+        }
+    }
+    else
+    {
+        annot = this->oh;
+    }
+    if (! annot.isInitialized())
+    {
+        QTC::TC("qpdf", "QPDFObjectHandle broken checkbox");
+        this->oh.warnIfPossible(
+            "unable to set the value of this checkbox");
+        return;
+    }
+    QTC::TC("qpdf", "QPDFFormFieldObjectHelper set checkbox AS");
+    annot.replaceKey("/AS", name);
+}

qpdf/qpdf.testcov

@@ -390,3 +390,11 @@ QPDFObjectHandle replace with copy 0
 QPDFPageDocumentHelper indirect as resources 0
 QPDFAnnotationObjectHelper forbidden flags 0
 QPDFAnnotationObjectHelper missing required flags 0
+QPDFFormFieldObjectHelper set parent radio button 0
+QPDFFormFieldObjectHelper radio button grandkid widget 0
+QPDFFormFieldObjectHelper turn on radio button 0
+QPDFFormFieldObjectHelper turn off radio button 0
+QPDFFormFieldObjectHelper checkbox kid widget 0
+QPDFObjectHandle broken radio button 0
+QPDFFormFieldObjectHelper set checkbox AS 0
+QPDFObjectHandle broken checkbox 0

qpdf/qtest/qpdf.test

@@ -188,7 +188,7 @@ my @form_tests = (
     'form-errors',
     );
 
-$n_tests += scalar(@form_tests) + 2;
+$n_tests += scalar(@form_tests) + 6;
 
 # Many of the form*.pdf files were created by converting the
 # LibreOffice document storage/form.odt to PDF and then manually
@@ -216,6 +216,22 @@ $td->runtest("compare files",
              {$td->FILE => "a.pdf"},
              {$td->FILE => "form-no-need-appearances-filled.pdf"});
 
+$td->runtest("button fields",
+             {$td->COMMAND => "test_driver 51 button-set.pdf"},
+             {$td->FILE => "button-set.out", $td->EXIT_STATUS => 0},
+             $td->NORMALIZE_NEWLINES);
+$td->runtest("compare files",
+             {$td->FILE => "a.pdf"},
+             {$td->FILE => "button-set-out.pdf"});
+
+$td->runtest("broken button fields",
+             {$td->COMMAND => "test_driver 51 button-set-broken.pdf"},
+             {$td->FILE => "button-set-broken.out", $td->EXIT_STATUS => 0},
+             $td->NORMALIZE_NEWLINES);
+$td->runtest("compare files",
+             {$td->FILE => "a.pdf"},
+             {$td->FILE => "button-set-broken-out.pdf"});
+
 show_ntests();
 # ----------
 $td->notify("--- Stream Replacement Tests ---");

qpdf/qtest/qpdf/button-set-broken.out

@@ -0,0 +1,7 @@
+setting r1 via parent
+WARNING: button-set-broken.pdf, object 5 0 at offset 995: unable to set the value of this radio button
+turning checkbox1 on
+turning checkbox2 off
+WARNING: button-set-broken.pdf, object 7 0 at offset 1354: unable to set the value of this checkbox
+setting r2 via child
+test 51 done

qpdf/qtest/qpdf/button-set.out

@@ -0,0 +1,5 @@
+setting r1 via parent
+turning checkbox1 on
+turning checkbox2 off
+setting r2 via child
+test 51 done

qpdf/test_driver.cc

@@ -1771,6 +1771,55 @@ void runtest(int n, char const* filename1, char const* arg2)
             std::cout << *iter << std::endl;
         }
     }
+    else if (n == 51)
+    {
+        // Test radio button and checkbox field setting. The input
+        // files must have radios button called r1 and r2 and
+        // checkboxes called checkbox1 and checkbox2. The files
+        // button-set*.pdf are designed for this test case.
+        QPDFObjectHandle acroform = pdf.getRoot().getKey("/AcroForm");
+        QPDFObjectHandle fields = acroform.getKey("/Fields");
+        int n = fields.getArrayNItems();
+        for (int i = 0; i < n; ++i)
+        {
+            QPDFObjectHandle field = fields.getArrayItem(i);
+            QPDFObjectHandle T = field.getKey("/T");
+            if (! T.isString())
+            {
+                continue;
+            }
+            std::string Tval = T.getUTF8Value();
+            if (Tval == "r1")
+            {
+                std::cout << "setting r1 via parent\n";
+                QPDFFormFieldObjectHelper foh(field);
+                foh.setV(QPDFObjectHandle::newName("/2"));
+            }
+            else if (Tval == "r2")
+            {
+                std::cout << "setting r2 via child\n";
+                field = field.getKey("/Kids").getArrayItem(1);
+                QPDFFormFieldObjectHelper foh(field);
+                foh.setV(QPDFObjectHandle::newName("/3"));
+            }
+            else if (Tval == "checkbox1")
+            {
+                std::cout << "turning checkbox1 on\n";
+                QPDFFormFieldObjectHelper foh(field);
+                foh.setV(QPDFObjectHandle::newName("/Yes"));
+            }
+            else if (Tval == "checkbox2")
+            {
+                std::cout << "turning checkbox2 off\n";
+                QPDFFormFieldObjectHelper foh(field);
+                foh.setV(QPDFObjectHandle::newName("/Off"));
+            }
+        }
+        QPDFWriter w(pdf, "a.pdf");
+	w.setQDFMode(true);
+        w.setStaticID(true);
+        w.write();
+    }
     else
     {
 	throw std::runtime_error(std::string("invalid test ") +