Embind: Allow UNO sequences to be constructed from JS arrays

...though

> let seq = new Module.uno_Sequence_string(["foo", "bar", "baz"]);
> // ...
> delete seq;

is still ugly.

And Embind only allows for overload resolution by number of parameters, not by
their type, so using the original sequence constructor had to be changed to

> let seq = new Module.uno_Sequence_string(3, Module.uno_Sequence.FromSize);
> seq.set(0, "foo");
> seq.set(1, "bar");
> seq.set(2, "baz");
> // ...
> delete seq;

Change-Id: If26ff4a485ba16b65cf24b6fe729d379c733c473
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/163097
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <stephan.bergmann@allotropia.de>

1 files changed, 22 insertions, 1 deletions

diff --git a/include/static/unoembindhelpers/PrimaryBindings.hxx b/include/static/unoembindhelpers/PrimaryBindings.hxx
index 61efaf01153b..4df301277cc9 100644
--- a/include/static/unoembindhelpers/PrimaryBindings.hxx
+++ b/include/static/unoembindhelpers/PrimaryBindings.hxx
@@ -11,6 +11,8 @@
 
 #include <sal/config.h>
 
+#include <cstdint>
+#include <limits>
 #include <stdexcept>
 
 #include <emscripten/bind.h>
@@ -36,6 +38,11 @@ enum class uno_Reference
     FromAny
 };
 
+enum class uno_Sequence
+{
+    FromSize
+};
+
 template <typename T> struct UnoInOutParam
 {
     UnoInOutParam() {}
@@ -72,7 +79,21 @@ void checkSequenceAccess(css::uno::Sequence<T> const& sequence, sal_Int32 index)
 template <typename T> void registerSequence(char const* name)
 {
     emscripten::class_<css::uno::Sequence<T>>(name)
-        .constructor(+[](sal_Int32 size) {
+        .constructor(+[](emscripten::val const& members) {
+            auto const len = members["length"].as<std::uint32_t>();
+            if (len > std::numeric_limits<sal_Int32>::max())
+            {
+                throw std::length_error("JavaScript array length too large for C++ UNO sequence");
+            }
+            css::uno::Sequence<T> seq(len);
+            auto const p = seq.getArray();
+            for (std::uint32_t i = 0; i != len; ++i)
+            {
+                p[i] = members[i].as<T>();
+            }
+            return seq;
+        })
+        .constructor(+[](sal_Int32 size, [[maybe_unused]] uno_Sequence) {
             checkSequenceSize(size);
             return css::uno::Sequence<T>(size);
         })