Add path to get different DPI drawables

Allow a caller to request a different density than their current display
allows. This can mean a device displaying mdpi can get a resource that's
in hdpi and have it pretend to be in mdpi resolution. If a drawable
that's returned is not in the requested density, it will set it at the
appropriate density to be scaled up later on.

The API for this is hidden currently.

Bug: 3134688
Change-Id: I6c3908cbdef4907b8d3f1576df9e3b0e7af1755a

2 files changed, 39 insertions, 13 deletions

diff --git a/include/utils/ResourceTypes.h b/include/utils/ResourceTypes.h
index da86da4..ed7f53d 100644
--- a/include/utils/ResourceTypes.h
+++ b/include/utils/ResourceTypes.h
@@ -1771,12 +1771,14 @@ public:
      *
      * @return ssize_t Either a >= 0 table index or a negative error code.
      */
-    ssize_t getResource(uint32_t resID, Res_value* outValue, bool mayBeBag=false,
-            uint32_t* outSpecFlags=NULL, ResTable_config* outConfig=NULL) const;
+    ssize_t getResource(uint32_t resID, Res_value* outValue, bool mayBeBag = false,
+                    uint16_t density = 0,
+                    uint32_t* outSpecFlags = NULL,
+                    ResTable_config* outConfig = NULL) const;
 
     inline ssize_t getResource(const ResTable_ref& res, Res_value* outValue,
             uint32_t* outSpecFlags=NULL) const {
-        return getResource(res.ident, outValue, false, outSpecFlags, NULL);
+        return getResource(res.ident, outValue, false, 0, outSpecFlags, NULL);
     }
 
     ssize_t resolveReference(Res_value* inOutValue,
diff --git a/libs/utils/ResourceTypes.cpp b/libs/utils/ResourceTypes.cpp
index 91e7df3..03d2e21 100644
--- a/libs/utils/ResourceTypes.cpp
+++ b/libs/utils/ResourceTypes.cpp
@@ -1896,7 +1896,7 @@ bool ResTable::getResourceName(uint32_t resID, resource_name* outName) const
     return false;
 }
 
-ssize_t ResTable::getResource(uint32_t resID, Res_value* outValue, bool mayBeBag,
+ssize_t ResTable::getResource(uint32_t resID, Res_value* outValue, bool mayBeBag, uint16_t density,
         uint32_t* outSpecFlags, ResTable_config* outConfig) const
 {
     if (mError != NO_ERROR) {
@@ -1926,7 +1926,7 @@ ssize_t ResTable::getResource(uint32_t resID, Res_value* outValue, bool mayBeBag
     memset(&bestItem, 0, sizeof(bestItem)); // make the compiler shut up
 
     if (outSpecFlags != NULL) *outSpecFlags = 0;
-    
+
     // Look through all resource packages, starting with the most
     // recently added.
     const PackageGroup* const grp = mPackageGroups[p];
@@ -1934,6 +1934,22 @@ ssize_t ResTable::getResource(uint32_t resID, Res_value* outValue, bool mayBeBag
         LOGW("Bad identifier when getting value for resource number 0x%08x", resID);
         return BAD_INDEX;
     }
+
+    // Allow overriding density
+    const ResTable_config* desiredConfig = &mParams;
+    ResTable_config* overrideConfig = NULL;
+    if (density > 0) {
+        overrideConfig = (ResTable_config*) malloc(sizeof(ResTable_config));
+        if (overrideConfig == NULL) {
+            LOGE("Couldn't malloc ResTable_config for overrides: %s", strerror(errno));
+            return BAD_INDEX;
+        }
+        memcpy(overrideConfig, &mParams, sizeof(ResTable_config));
+        overrideConfig->density = density;
+        desiredConfig = overrideConfig;
+    }
+
+    ssize_t rc = BAD_INDEX;
     size_t ip = grp->packages.size();
     while (ip > 0) {
         ip--;
@@ -1943,12 +1959,13 @@ ssize_t ResTable::getResource(uint32_t resID, Res_value* outValue, bool mayBeBag
         const ResTable_type* type;
         const ResTable_entry* entry;
         const Type* typeClass;
-        ssize_t offset = getEntry(package, t, e, &mParams, &type, &entry, &typeClass);
+        ssize_t offset = getEntry(package, t, e, desiredConfig, &type, &entry, &typeClass);
         if (offset <= 0) {
             if (offset < 0) {
                 LOGW("Failure getting entry for 0x%08x (t=%d e=%d) in package %zd (error %d)\n",
                         resID, t, e, ip, (int)offset);
-                return offset;
+                rc = offset;
+                goto out;
             }
             continue;
         }
@@ -1963,13 +1980,14 @@ ssize_t ResTable::getResource(uint32_t resID, Res_value* outValue, bool mayBeBag
 
         TABLE_NOISY(aout << "Resource type data: "
               << HexDump(type, dtohl(type->header.size)) << endl);
-        
+
         if ((size_t)offset > (dtohl(type->header.size)-sizeof(Res_value))) {
             LOGW("ResTable_item at %d is beyond type chunk data %d",
                  (int)offset, dtohl(type->header.size));
-            return BAD_TYPE;
+            rc = BAD_TYPE;
+            goto out;
         }
-        
+
         const Res_value* item =
             (const Res_value*)(((const uint8_t*)type) + offset);
         ResTable_config thisConfig;
@@ -2011,10 +2029,16 @@ ssize_t ResTable::getResource(uint32_t resID, Res_value* outValue, bool mayBeBag
                          outValue->data, &len)).string()
                      : "",
                      outValue->data));
-        return bestPackage->header->index;
+        rc = bestPackage->header->index;
+        goto out;
+    }
+
+out:
+    if (overrideConfig != NULL) {
+        free(overrideConfig);
     }
 
-    return BAD_VALUE;
+    return rc;
 }
 
 ssize_t ResTable::resolveReference(Res_value* value, ssize_t blockIndex,
@@ -2027,7 +2051,7 @@ ssize_t ResTable::resolveReference(Res_value* value, ssize_t blockIndex,
         if (outLastRef) *outLastRef = value->data;
         uint32_t lastRef = value->data;
         uint32_t newFlags = 0;
-        const ssize_t newIndex = getResource(value->data, value, true, &newFlags,
+        const ssize_t newIndex = getResource(value->data, value, true, 0, &newFlags,
                 outConfig);
         if (newIndex == BAD_INDEX) {
             return BAD_INDEX;