Provide a way for authors to center adventure text

games/gorreven.arch

@@ -122,13 +122,13 @@ methods
 >>my life won't be worth a fake dollar bill.  None of our lives will.
 >>
 >>
->>                         Derek Jones Presents...
->>
->>                        an Archetype Adventure
->>
->>                         "The Gorreven Papers"
->>
->>
+      write_centered "Derek Jones Presents..."
+      write
+      write_centered "an Archetype Adventure"
+      write
+      write_centered "\"The Gorreven Papers\""
+      write
+      write
     }  # FIRSTDESC
 
   'LONGDESC' :

games/starship.arch

@@ -96,13 +96,13 @@ methods
 >>
 >>Who am I...?
 >>
->>                       Derek Jones Presents
->>
->>                      an Archetype Adventure
->>
->>                       STARSHIP  SOLITAIRE
->>
->>
+      write_centered "Derek Jones Presents"
+      write
+      write_centered "an Archetype Adventure"
+      write
+      write_centered "STARSHIP  SOLITAIRE"
+      write
+      write
     }  # FIRSTDESC
 
   'LONGDESC' : {

src/Keywords.cc

@@ -68,6 +68,7 @@ namespace archetype {
         RESERVE(RW_WHILE, "while");
         RESERVE(RW_WRITE, "write");
         RESERVE(RW_WRITES, "writes");
+        RESERVE(RW_WRITE_CENTERED, "write_centered");
 
         OPERATOR(OP_PAIR, "@");
         OPERATOR(OP_CONCAT, "&");

src/Keywords.hh

@@ -52,6 +52,7 @@ namespace archetype {
             RW_WHILE,
             RW_WRITE,
             RW_WRITES,
+            RW_WRITE_CENTERED,
             RW_WRITE_PARAGRAPH,
             NumReserved
         };

src/Statement.cc

@@ -477,6 +477,10 @@ namespace archetype {
 
     Value OutputStatement::execute() const {
         Value last_value(new UndefinedValue);
+        unique_ptr<ostringstream> centered;
+        if (writeType_ == Keywords::RW_WRITE_CENTERED) {
+            centered.reset(new ostringstream);
+        }
         for (auto const& expr : expressions_) {
             last_value = expr->evaluate();
             if (writeType_ == Keywords::RW_DISPLAY) {
@@ -488,10 +492,16 @@ namespace archetype {
             }
             Value v_s = last_value->stringConversion();
             if (v_s->isDefined()) {
-                Universe::instance().output()->put(v_s->getString());
+                if (centered) {
+                    *centered << v_s->getString();
+                } else {
+                    Universe::instance().output()->put(v_s->getString());
+                }
             }
         }
-        if (writeType_ != Keywords::RW_WRITES) {
+        if (centered) {
+            Universe::instance().output()->center(centered->str());
+        } else if (writeType_ != Keywords::RW_WRITES) {
             Universe::instance().output()->endLine();
         }
         if (writeType_ == Keywords::RW_STOP) {
@@ -766,6 +776,7 @@ namespace archetype {
                 case Keywords::RW_DISPLAY:
                 case Keywords::RW_WRITE:
                 case Keywords::RW_WRITES:
+                case Keywords::RW_WRITE_CENTERED:
                 case Keywords::RW_STOP:
                     the_stmt.reset(new OutputStatement(word));
                     break;

src/TestStatement.cc

@@ -87,6 +87,14 @@ namespace archetype {
         string expected_4_2 = "Hello, world!\n";
         ARCHETYPE_TEST_EQUAL(actual_4_2, expected_4_2);
 
+        // Capture uses a bare StringOutput, so center() falls through to the
+        // default put+endLine; padding math is covered in TestWrappedOutput.
+        Statement stmt4c = make_stmt_from_str("write_centered \"Hello, \", \"world!\"");
+        ARCHETYPE_TEST(stmt4c != nullptr);
+        Capture capture4c;
+        stmt4c->execute();
+        ARCHETYPE_TEST_EQUAL(capture4c.getCapture(), string("Hello, world!\n"));
+
         Statement stmt5 = make_stmt_from_str(">>Now, this is a \"quote\".");
         ARCHETYPE_TEST(stmt5 != nullptr);
         Capture capture5;

src/TestWrappedOutput.cc

@@ -50,7 +50,44 @@ namespace archetype {
         out() << "TestWrappedOutput finished." << endl;
     }
 
+    void TestWrappedOutput::testCenter_() {
+        UserOutput user_soutput{new StringOutput};
+        StringOutput& strout(*dynamic_cast<StringOutput*>(user_soutput.get()));
+        UserOutput user_output{new WrappedOutput{user_soutput}};
+        WrappedOutput& wrout(*dynamic_cast<WrappedOutput*>(user_output.get()));
+
+        auto delta = [&](size_t& mark) {
+            string all = strout.getOutput();
+            string d = all.substr(mark);
+            mark = all.size();
+            return d;
+        };
+        size_t mark = 0;
+
+        wrout.setMaxColumns(20);
+        user_output->center("Hello");
+        // (20 - 5) / 2 = 7 leading spaces
+        ARCHETYPE_TEST_EQUAL(delta(mark), string("       Hello\n"));
+
+        // A line at the column count gets no padding.
+        wrout.setMaxColumns(5);
+        user_output->center("Hello");
+        ARCHETYPE_TEST_EQUAL(delta(mark), string("Hello\n"));
+
+        // A line wider than the column count gets no padding.
+        user_output->center("Hello, world!");
+        ARCHETYPE_TEST_EQUAL(delta(mark), string("Hello, world!\n"));
+
+        // Zero columns means indeterminate width: emit unpadded.
+        wrout.setMaxColumns(0);
+        user_output->center("X");
+        ARCHETYPE_TEST_EQUAL(delta(mark), string("X\n"));
+
+        out() << "TestWrappedOutput::testCenter_ finished." << endl;
+    }
+
     void TestWrappedOutput::runTests_() {
         testBasicWrap_();
+        testCenter_();
     }
 }

src/TestWrappedOutput.hh

@@ -14,6 +14,7 @@
 namespace archetype {
     class TestWrappedOutput : public ITestSuite {
         void testBasicWrap_();
+        void testCenter_();
     protected:
         virtual void runTests_() override;
     public:

src/UserOutput.hh

@@ -24,6 +24,7 @@ namespace archetype {
         virtual void endLine() = 0;
         virtual void resetPager() { }
         virtual void banner(char ch) = 0;
+        virtual void center(const std::string& line) { put(line); endLine(); }
     };
     typedef std::shared_ptr<IUserOutput> UserOutput;
 }

src/WrappedOutput.cc

@@ -80,6 +80,18 @@ namespace archetype {
         resetCursor();
     }
 
+    void WrappedOutput::center(const std::string& line) {
+        if (cursor_ != 0) {
+            endLine();
+        }
+        if (maxColumns_ > 0 and int(line.size()) < maxColumns_) {
+            int pad = (maxColumns_ - int(line.size())) / 2;
+            output_->put(string(pad, ' '));
+        }
+        output_->put(line);
+        endLine();
+    }
+
     void WrappedOutput::banner(char ch) {
         if (cursor_ != 0) {
             endLine();

src/WrappedOutput.hh

@@ -23,6 +23,7 @@ namespace archetype {
         virtual void put(const std::string& line) override;
         virtual void endLine() override;
         virtual void banner(char ch) override;
+        virtual void center(const std::string& line) override;
 
         // Get and set the columns of text available in the console.
         // Zero is a special value meaning that the columns are

src/main.cc

@@ -58,11 +58,7 @@ namespace archetype {
 
         ~Session() {
             if (not silent_) {
-                UserOutput output = Universe::instance().output();
-                output->endLine();
-                output->put("Archetype ");
-                output->put(VersionString);
-                output->endLine();
+                std::cerr << "Archetype " << VersionString << std::endl;
             }
             TestRegistry::destroy();
             Universe::destroy();