PDF interactive forms (AcroForms) in Obj-C

//---------------------------------------------------------------------------------------
// Copyright (c) 2001-2023 by Apryse Software Inc. All Rights Reserved.
// Consult legal.txt regarding legal and license information.
//---------------------------------------------------------------------------------------

#import <OBJC/PDFNetOBJC.h>
#import <Foundation/Foundation.h>
#import <Foundation/NSDictionary.h>
#import <Foundation/NSArray.h>

//---------------------------------------------------------------------------------------
// This sample illustrates basic PDFNet capabilities related to interactive
// forms (also known as AcroForms).
//---------------------------------------------------------------------------------------

// field_nums has to be greater than 0.
void RenameAllFields(PTPDFDoc* doc, NSString* name, int field_nums)
{
    PTFieldIterator * itr = [doc GetFieldIteratorWithName: name];
    int counter;
    for (counter=1; [itr HasNext]; itr=[doc GetFieldIteratorWithName: name], ++counter)
    {
        PTField *f = [itr Current];
    int update_count = (int)(ceil(counter/(double)field_nums));
        [f Rename: [name stringByAppendingFormat: @"-%d", update_count]];
    }
}

PTObj* CreateCustomButtonAppearance(PTPDFDoc* doc, bool button_down)
{
    // Create a button appearance stream ------------------------------------
    PTElementBuilder *build = [[PTElementBuilder alloc] init];
    PTElementWriter *writer = [[PTElementWriter alloc] init];
    [writer WriterBeginWithSDFDoc: [doc GetSDFDoc] compress: YES];
    
    // Draw background
    PTElement *element = [build CreateRect: 0 y: 0 width: 101 height: 137];
    [element SetPathFill: YES];
    [element SetPathStroke: NO];
    [[element GetGState] SetFillColorSpace: [PTColorSpace CreateDeviceGray]];
    [[element GetGState] SetFillColorWithColorPt: [[PTColorPt alloc] initWithX: 0.75 y: 0 z: 0 w: 0]];
    [writer WriteElement: element];
    
    // Draw 'Submit' text
    [writer WriteElement: [build CreateTextBegin]];
    {
        NSString *text = @"Submit";
        element = [build CreateTextRunWithFont: text font: [PTFont Create: [doc GetSDFDoc] type: e_pthelvetica_bold embed: NO] font_sz: 12];
        [[element GetGState] SetFillColorWithColorPt: [[PTColorPt alloc] initWithX: 0 y: 0 z: 0 w: 0]];
        
        if (button_down)
            [element SetTextMatrixWithMatrix2D: [[PTMatrix2D alloc] initWithA: 1 b: 0 c: 0 d: 1 h: 33 v: 10]];
        else
            [element SetTextMatrixWithMatrix2D: [[PTMatrix2D alloc] initWithA: 1 b: 0 c: 0 d: 1 h: 30 v: 13]];
        [writer WriteElement: element];
    }
    [writer WriteElement: [build CreateTextEnd]];
    
    PTObj * stm = [writer End];
    
    // Set the bounding box
    [stm PutRect: @"BBox" x1: 0 y1: 0 x2: 101 y2: 37];
    [stm PutName: @"Subtype" name: @"Form"];
    return stm;
}

int main(int argc, char *argv[])
{
    @autoreleasepool {
        int ret = 0;
        [PTPDFNet Initialize: 0];
        
        // The vector used to store the name and count of all fields.
        // This is used later on to clone the fields
        NSMutableDictionary  *field_names = [[NSMutableDictionary alloc] init];
        
        //----------------------------------------------------------------------------------
        // Example 1: Programatically create new Form Fields and Widget Annotations.
        //----------------------------------------------------------------------------------
        @try
        {
            PTPDFDoc *doc = [[PTPDFDoc alloc] init];
            // Create a blank new page and add some form fields.
            PTPage *blank_page = [doc PageCreate: [[PTPDFRect alloc] initWithX1: 0 y1: 0 x2: 612 y2: 792]];
            
            // Text Widget Creation
            // Create an empty text widget with black text.
            PTTextWidget *text1 = [PTTextWidget Create: doc pos: [[PTPDFRect alloc] initWithX1: 110 y1: 700 x2: 380 y2: 730] field_name: @""];
            [text1 SetText: @"Basic Text Field"];
            [text1 RefreshAppearance];
            [blank_page AnnotPushBack: text1];
            // Create a vertical text widget with blue text and a yellow background.
            PTTextWidget *text2 = [PTTextWidget Create: doc pos: [[PTPDFRect alloc] initWithX1: 50 y1: 400 x2: 90 y2: 730] field_name: @""];
            [text2 SetRotation: 90];
            // Set the text content.
            [text2 SetText: @"    ****Lucky Stars!****"];
            // Set the font type, text color, font size, border color and background color.
            [text2 SetFont: [PTFont Create: [doc GetSDFDoc] type: e_pthelvetica_oblique embed: NO]];
            [text2 SetFontSize: 28];
            [text2 SetTextColor: [[PTColorPt alloc] initWithX: 0 y: 0 z: 1 w: 0] col_comp: 3];
            [text2 SetBorderColor: [[PTColorPt alloc] initWithX: 0 y: 0 z: 0 w: 0] compnum: 3];
            [text2 SetBackgroundColor: [[PTColorPt alloc] initWithX: 1 y: 1 z: 0 w: 0] compnum: 3];
            [text2 RefreshAppearance];
            // Add the annotation to the page.
            [blank_page AnnotPushBack: text2];
            // Create two new text widget with Field names employee.name.first and employee.name.last
            // This logic shows how these widgets can be created using either a field name string or
            // a Field object
            PTTextWidget *text3 = [PTTextWidget Create: doc pos: [[PTPDFRect alloc] initWithX1: 110 y1: 660 x2: 380 y2: 690] field_name: @"employee.name.first"];
            [text3 SetText: @"Levi"];
            [text3 SetFont: [PTFont Create: [doc GetSDFDoc] type: e_pttimes_bold embed: NO]];
            [text3 RefreshAppearance];
            [blank_page AnnotPushBack: text3];
            PTField *emp_last_name = [doc FieldCreateWithString: @"employee.name.last" type: e_pttext field_value: @"Ackerman" def_field_value: @""];
            PTTextWidget *text4 = [PTTextWidget CreateWithField: doc pos: [[PTPDFRect alloc] initWithX1: 110 y1: 620 x2: 380 y2: 650] field: emp_last_name];
            [text4 SetFont: [PTFont Create: [doc GetSDFDoc] type: e_pttimes_bold embed: NO]];
            [text4 RefreshAppearance];
            [blank_page AnnotPushBack: text4];
            
            // Signature Widget Creation (unsigned)
            PTSignatureWidget *signature1 = [PTSignatureWidget Create: doc pos: [[PTPDFRect alloc] initWithX1: 110 y1: 560 x2: 260 y2: 610] field_name: @""];
            [signature1 RefreshAppearance];
            [blank_page AnnotPushBack: signature1];
            
            // CheckBox Widget Creation
            // Create a check box widget that is not checked.
            PTCheckBoxWidget *check1 = [PTCheckBoxWidget Create: doc pos: [[PTPDFRect alloc] initWithX1: 140 y1: 490 x2: 170 y2: 520] field_name: @""];
            [check1 RefreshAppearance];
            [blank_page AnnotPushBack: check1];
            // Create a check box widget that is checked.
            PTCheckBoxWidget *check2 = [PTCheckBoxWidget Create: doc pos: [[PTPDFRect alloc] initWithX1: 190 y1: 490 x2: 250 y2: 540] field_name: @"employee.name.check1"];
            [check2 SetBackgroundColor: [[PTColorPt alloc] initWithX: 1 y: 1 z: 1 w: 0] compnum: 3];
            [check2 SetBorderColor: [[PTColorPt alloc] initWithX: 0 y: 0 z: 0 w: 0] compnum: 3];
            // Check the widget (by default it is unchecked).
            [check2 SetChecked: true];
            [check2 RefreshAppearance];
            [blank_page AnnotPushBack: check2];
            
            // PushButton Widget Creation
            PTPushButtonWidget *pushbutton1 = [PTPushButtonWidget Create: doc pos: [[PTPDFRect alloc] initWithX1: 380 y1: 490 x2: 520 y2: 540] field_name: @""];
            [pushbutton1 SetTextColor: [[PTColorPt alloc] initWithX: 1 y: 1 z: 1 w: 0] col_comp: 3];
            [pushbutton1 SetFontSize: 36];
            [pushbutton1 SetBackgroundColor: [[PTColorPt alloc] initWithX: 0 y: 0 z: 0 w: 0] compnum: 3];
            // Add a caption for the pushbutton.
            [pushbutton1 SetStaticCaptionText: @"PushButton"];
            [pushbutton1 RefreshAppearance];
            [blank_page AnnotPushBack: pushbutton1];
            
            // ComboBox Widget Creation
            PTComboBoxWidget *combo1 = [PTComboBoxWidget Create: doc pos: [[PTPDFRect alloc] initWithX1: 280 y1: 560 x2: 580 y2: 610] field_name: @""];
            // Add options to the combobox widget.
            [combo1 AddOption: @"Combo Box No.1"];
            [combo1 AddOption: @"Combo Box No.2"];
            [combo1 AddOption: @"Combo Box No.3"];
            // Make one of the options in the combo box selected by default.
            [combo1 SetSelectedOption: @"Combo Box No.2"];
            [combo1 SetTextColor: [[PTColorPt alloc] initWithX: 1 y: 0 z: 0 w: 0] col_comp: 3];
            [combo1 SetFontSize: 28];
            [combo1 RefreshAppearance];
            [blank_page AnnotPushBack: combo1];
            
            // ListBox Widget Creation
            PTListBoxWidget *list1 = [PTListBoxWidget Create: doc pos: [[PTPDFRect alloc] initWithX1: 400 y1: 620 x2: 580 y2: 730] field_name: @""];
            // Add one option to the listbox widget.
            [list1 AddOption: @"List Box No.1"];
            // Add multiple options to the listbox widget in a batch.
            NSArray *list_options = [NSArray arrayWithObjects: @"List Box No.2", @"List Box No.3", nil];
            [list1 AddOptions: list_options];
            // Select some of the options in list box as default options
            [list1 SetSelectedOptions: list_options];
            // Enable list box to have multi-select when editing.
            [[list1 GetField] SetFlag: e_ptmultiselect value: true];
            [list1 SetFont: [PTFont Create: [doc GetSDFDoc] type: e_pttimes_italic embed: NO]];
            [list1 SetTextColor: [[PTColorPt alloc] initWithX: 1 y: 0 z: 0 w: 0] col_comp: 3];
            [list1 SetFontSize: 28];
            [list1 SetBackgroundColor: [[PTColorPt alloc] initWithX: 1 y: 1 z: 1 w: 0] compnum: 3];
            [list1 RefreshAppearance];
            [blank_page AnnotPushBack: list1];
            
            // RadioButton Widget Creation
            // Create a radio button group and add three radio buttons in it.
            PTRadioButtonGroup *radio_group = [PTRadioButtonGroup Create: doc field_name: @"RadioGroup"];
            PTRadioButtonWidget *radiobutton1 = [radio_group Add: [[PTPDFRect alloc] initWithX1: 140 y1: 410 x2: 190 y2: 460] onstate: @""];
            [radiobutton1 SetBackgroundColor: [[PTColorPt alloc] initWithX: 1 y: 1 z: 0 w: 0] compnum: 3];
            [radiobutton1 RefreshAppearance];
            PTRadioButtonWidget *radiobutton2 = [radio_group Add: [[PTPDFRect alloc] initWithX1: 310 y1: 410 x2: 360 y2: 460] onstate: @""];
            [radiobutton2 SetBackgroundColor: [[PTColorPt alloc] initWithX: 0 y: 1 z: 0 w: 0] compnum: 3];
            [radiobutton2 RefreshAppearance];
            PTRadioButtonWidget *radiobutton3 = [radio_group Add: [[PTPDFRect alloc] initWithX1: 480 y1: 410 x2: 530 y2: 460] onstate: @""];
            // Enable the third radio button. By default the first one is selected
            [radiobutton3 EnableButton];
            [radiobutton3 SetBackgroundColor: [[PTColorPt alloc] initWithX: 0 y: 1 z: 1 w: 0] compnum: 3];
            [radiobutton3 RefreshAppearance];
            [radio_group AddGroupButtonsToPage: blank_page];
            
            // Custom push button annotation creation
            PTPushButtonWidget *custom_pushbutton1 = [PTPushButtonWidget Create: doc pos: [[PTPDFRect alloc] initWithX1: 260 y1: 320 x2: 360 y2: 360] field_name: @""];
            // Set the annotation appearance.
            [custom_pushbutton1 SetAppearance: CreateCustomButtonAppearance(doc, NO) annot_state: e_ptnormal app_state: nil];
            // Create 'SubmitForm' action. The action will be linked to the button.
            PTFileSpec *url = [PTFileSpec CreateURL: [doc GetSDFDoc] url: @"http://www.pdftron.com"];
            PTAction *button_action = [PTAction CreateSubmitForm: url];
            // Associate the above action with 'Down' event in annotations action dictionary.
            PTObj * annot_action = [[custom_pushbutton1 GetSDFObj] PutDict: @"AA"];
            [annot_action Put: @"D" obj: [button_action GetSDFObj]];
            [blank_page AnnotPushBack: custom_pushbutton1];
            
            // Add the page as the last page in the document.
            [doc PagePushBack: blank_page];
            
            // If you are not satisfied with the look of default auto-generated appearance
            // streams you can delete "AP" entry from the Widget annotation and set
            // "NeedAppearances" flag in AcroForm dictionary:
            //    doc.GetAcroForm().PutBool("NeedAppearances", true);
            // This will force the viewer application to auto-generate new appearance streams
            // every time the document is opened.
            //
            // Alternatively you can generate custom annotation appearance using ElementWriter
            // and then set the "AP" entry in the widget dictionary to the new appearance
            // stream.
            //
            // Yet another option is to pre-populate field entries with dummy text. When
            // you edit the field values using PDFNet the new field appearances will match
            // the old ones.
            
            //doc.GetAcroForm().PutBool("NeedAppearances", true);
            [doc RefreshFieldAppearances];
            
            [doc SaveToFile: @"../../TestFiles/Output/forms_test1.pdf" flags: 0];
            printf("Done.\n");
        }
        @catch (NSException *e)
        {
            NSLog(@"%@", e.reason);
            ret = 1;
        }
        
        //----------------------------------------------------------------------------------
        // Example 2:
        // Fill-in forms / Modify values of existing fields.
        // Traverse all form fields in the document (and print out their names).
        // Search for specific fields in the document.
        //----------------------------------------------------------------------------------
        @try
        {
            PTPDFDoc *doc = [[PTPDFDoc alloc] initWithFilepath: @"../../TestFiles/Output/forms_test1.pdf"];
            [doc InitSecurityHandler];
            
            PTFieldIterator * itr = [doc GetFieldIterator];
            for(; [itr HasNext]; [itr Next])
            {
                NSString *cur_field_name = [[itr Current] GetName];
                // Add one to the count for this field name for later processing
                if ([field_names objectForKey: cur_field_name] != nil)
                {
                    int same_field_name_count = [[field_names objectForKey: cur_field_name] intValue] + 1;
                    [field_names setObject: [NSNumber numberWithInt: same_field_name_count] forKey: cur_field_name];
                }
                else
                {
                    [field_names setObject: @"1" forKey: cur_field_name];
                }
                
                printf("Field name: %s\n", [[[itr Current] GetName] UTF8String]);
                printf("Field partial name: %s\n", [[[itr Current] GetPartialName] UTF8String]);
                
                printf("Field type: ");
                PTFieldType type = [[itr Current] GetType];
                NSString *str_val = [[itr Current] GetValueAsString];
                
                switch(type)
                {
                    case e_ptcheck:
                        [[itr Current] SetValueWithBool: YES];
                        printf("Check box: Value = %s\n", [str_val UTF8String]);
                        break;
                    case e_ptbutton:
                        printf("Button\n");
                        break;
                    case e_ptradio:
                        printf("Radio button: Value = %s\n", [str_val UTF8String]);
                        break;
                    case e_pttext:
                    {
                        printf("Text\n");
                        // Edit all variable text in the document
                        [[itr Current] SetValueWithString: [@"This is a new value. The old one was: " stringByAppendingString: str_val]];
                    }
                        break;
                    case e_ptchoice: printf("Choice\n"); break;
                    case e_ptsignature: printf("Signature\n"); break;
                    default: break;
                }
                
                printf("------------------------------\n");
            }
            
            // Search for a specific field
            PTField *f = [doc GetField: @"employee.name.first"];
            if (f)
            {
                printf("Field search for %s was successful\n", [[f GetName] UTF8String]);
            }
            else
            {
                printf("Field search failed \n");
            }
            
            // Regenerate field appearances.
            [doc RefreshFieldAppearances];
            [doc SaveToFile: @"../../TestFiles/Output/forms_test_edit.pdf" flags: 0];
            printf("Done.\n");
        }
        @catch(NSException *e)
        {
            NSLog(@"%@", e.reason);
            ret = 1;
        }
        
        //----------------------------------------------------------------------------------
        // Sample: Form templating
        // Replicate pages and form data within a document. Then rename field names to make
        // them unique.
        //----------------------------------------------------------------------------------
        @try
        {
            // Sample: Copying the page with forms within the same document
            PTPDFDoc *doc = [[PTPDFDoc alloc] initWithFilepath: @"../../TestFiles/Output/forms_test1.pdf"];
            [doc InitSecurityHandler];
            
            PTPage *src_page = [doc GetPage: 1];
            [doc PagePushBack: src_page];  // Append several copies of the first page
            [doc PagePushBack: src_page];     // Note that forms are successfully copied
            [doc PagePushBack: src_page];
            [doc PagePushBack: src_page];
            
            // Now we rename fields in order to make every field unique.
            // You can use this technique for dynamic template filling where you have a 'master'
            // form page that should be replicated, but with unique field names on every page.
            for (NSString* key in field_names)
            {
                RenameAllFields(doc, key, [[field_names valueForKey: key] intValue]);
            }
            
            [doc SaveToFile: @"../../TestFiles/Output/forms_test1_cloned.pdf" flags: 0];
            printf("Done.\n");
        }
        @catch(NSException *e)
        {
            NSLog(@"%@", e.reason);
            ret = 1;
        }
        
        //----------------------------------------------------------------------------------
        // Sample:
        // Flatten all form fields in a document.
        // Note that this sample is intended to show that it is possible to flatten
        // individual fields. PDFNet provides a utility function PDFDoc.FlattenAnnotations()
        // that will automatically flatten all fields.
        //----------------------------------------------------------------------------------
        @try
        {
            PTPDFDoc *doc = [[PTPDFDoc alloc] initWithFilepath: @"../../TestFiles/Output/forms_test1.pdf"];
            [doc InitSecurityHandler];
            
            // Traverse all pages
            if (true) {
                [doc FlattenAnnotations: NO];
            }
            else // Manual flattening
            {
                PTPageIterator *pitr;
                for (pitr = [doc GetPageIterator: 1];
                     [pitr HasNext]; [pitr Next])
                {
                    PTPage *page = [pitr Current];
                    for (int i = (int)[page GetNumAnnots] - 1; i >= 0; --i)
                    {
                        PTAnnot *annot = [page GetAnnot: i];
                        if ([annot GetType] == e_ptWidget)
                        {
                            [annot Flatten: page];
                        }
                    }
                }
            }
            
            [doc SaveToFile: @"../../TestFiles/Output/forms_test1_flattened.pdf" flags: 0];
            printf("Done.\n");
        }
        @catch(NSException *e)
        {
            NSLog(@"%@", e.reason);
            ret = 1;
        }
        [PTPDFNet Terminate: 0];        
        return ret;
    }
}