(c-api) Added resvg_get_image_bbox method.

Closes #140

5 files changed, 87 insertions, 4 deletions

diff --git a/capi/include/ResvgQt.h b/capi/include/ResvgQt.h
index d4516fc..53b44d7 100644
--- a/capi/include/ResvgQt.h
+++ b/capi/include/ResvgQt.h
@@ -216,6 +216,11 @@ public:
     QRectF boundsOnElement(const QString &id) const;
 
     /**
+     * @brief Returns bounding rectangle of a whole image.
+     */
+    QRectF boundingBox() const;
+
+    /**
      * @brief Returns \b true if element with such an ID exists.
      */
     bool elementExists(const QString &id) const;
@@ -380,6 +385,18 @@ inline QRectF ResvgRenderer::boundsOnElement(const QString &id) const
     return QRectF();
 }
 
+inline QRectF ResvgRenderer::boundingBox() const
+{
+    if (!d->tree)
+        return QRectF();
+
+    resvg_rect bbox;
+    if (resvg_get_image_bbox(d->tree, &bbox))
+        return QRectF(bbox.x, bbox.y, bbox.height, bbox.width);
+
+    return QRectF();
+}
+
 inline bool ResvgRenderer::elementExists(const QString &id) const
 {
     if (!d->tree)
diff --git a/capi/include/resvg.h b/capi/include/resvg.h
index 1a5bf4d..8702978 100644
--- a/capi/include/resvg.h
+++ b/capi/include/resvg.h
@@ -301,6 +301,8 @@ bool resvg_is_image_empty(const resvg_render_tree *tree);
 /**
  * @brief Returns an image size.
  *
+ * The size of a canvas that required to render this SVG.
+ *
  * @param tree Render tree.
  * @return Image size.
  */
@@ -315,6 +317,18 @@ resvg_size resvg_get_image_size(const resvg_render_tree *tree);
 resvg_rect resvg_get_image_viewbox(const resvg_render_tree *tree);
 
 /**
+ * @brief Returns an image bounding box.
+ *
+ * Can be smaller or bigger than a \b viewbox.
+ *
+ * @param tree Render tree.
+ * @param bbox Image's bounding box.
+ * @return \b false if an image has no elements.
+ */
+bool resvg_get_image_bbox(const resvg_render_tree *tree,
+                          resvg_rect *bbox);
+
+/**
  * @brief Returns \b true if a renderable node with such an ID exists.
  *
  * @param tree Render tree.
diff --git a/capi/qtests/tst_resvgqt.cpp b/capi/qtests/tst_resvgqt.cpp
index 72e8dec..c5bec64 100644
--- a/capi/qtests/tst_resvgqt.cpp
+++ b/capi/qtests/tst_resvgqt.cpp
@@ -15,6 +15,9 @@ private Q_SLOTS:
 
     void test_renderFile();
 
+    void test_imageSize();
+    void test_imageViewBox();
+    void test_imageBoundingBox();
     void test_elementExists();
     void test_transformForElement();
 };
@@ -66,6 +69,27 @@ void ResvgQtTests::test_renderFile()
 #endif
 }
 
+void ResvgQtTests::test_imageSize()
+{
+    ResvgRenderer render(localPath("vb.svg"));
+    QVERIFY(!render.isEmpty());
+    QCOMPARE(render.defaultSize(), QSize(200, 400));
+}
+
+void ResvgQtTests::test_imageViewBox()
+{
+    ResvgRenderer render(localPath("vb.svg"));
+    QVERIFY(!render.isEmpty());
+    QCOMPARE(render.viewBox(), QRect(50, 100, 200, 400));
+}
+
+void ResvgQtTests::test_imageBoundingBox()
+{
+    ResvgRenderer render(localPath("test.svg"));
+    QVERIFY(!render.isEmpty());
+    QCOMPARE(render.boundingBox(), QRect(20, 20, 160, 160));
+}
+
 void ResvgQtTests::test_elementExists()
 {
     ResvgRenderer render(localPath("test.svg"));
diff --git a/capi/qtests/vb.svg b/capi/qtests/vb.svg
new file mode 100644
index 0000000..7049b09
--- /dev/null
+++ b/capi/qtests/vb.svg
@@ -0,0 +1,3 @@
+<svg id="svg1" viewBox="50 100 200 400" xmlns="http://www.w3.org/2000/svg">
+    <circle id="circle1" cx="80" cy="100" r="40" fill="green" transform="scale(2)"/>
+</svg>
diff --git a/capi/src/lib.rs b/capi/src/lib.rs
index 3d31a7f..08d5dac 100644
--- a/capi/src/lib.rs
+++ b/capi/src/lib.rs
@@ -438,6 +438,20 @@ pub extern "C" fn resvg_cairo_render_to_canvas_by_id(
 }
 
 #[no_mangle]
+pub extern "C" fn resvg_is_image_empty(
+    tree: *const resvg_render_tree,
+) -> bool {
+    let tree = unsafe {
+        assert!(!tree.is_null());
+        &*tree
+    };
+
+    // The root/svg node should have at least two children.
+    // The first child is `defs` and it always present.
+    tree.0.root().children().count() > 1
+}
+
+#[no_mangle]
 pub extern "C" fn resvg_get_image_size(
     tree: *const resvg_render_tree,
 ) -> resvg_size {
@@ -473,18 +487,29 @@ pub extern "C" fn resvg_get_image_viewbox(
     }
 }
 
+
 #[no_mangle]
-pub extern "C" fn resvg_is_image_empty(
+pub extern "C" fn resvg_get_image_bbox(
     tree: *const resvg_render_tree,
+    bbox: *mut resvg_rect,
 ) -> bool {
     let tree = unsafe {
         assert!(!tree.is_null());
         &*tree
     };
 
-    // The root/svg node should have at least two children.
-    // The first child is `defs` and it always present.
-    tree.0.root().children().count() > 1
+    if let Some(r) = tree.0.root().calculate_bbox() {
+        unsafe {
+            (*bbox).x = r.x();
+            (*bbox).y = r.y();
+            (*bbox).width = r.width();
+            (*bbox).height = r.height();
+        }
+
+        true
+    } else {
+        false
+    }
 }
 
 #[no_mangle]