master f0d42c5e47e: Minor adjustments to Android drag and drop and content URIs

[Po Lu]

branch: master
commit f0d42c5e47eaba2c8ccee0a804965a2b71923d41
Author: Po Lu <luangruo@yahoo.com>
Commit: Po Lu <luangruo@yahoo.com>

    Minor adjustments to Android drag and drop and content URIs
    
    * java/org/gnu/emacs/EmacsWindow.java (EmacsWindow)
    <dndXPosition, dndYPosition>: New fields initialized to -1.
    (onDragEvent): Remember the position of the previous event to
    avoid sending duplicates.
    
    * src/androidvfs.c (EMACS_PATH_MAX): New define.
    (android_saf_tree_rename, android_saf_tree_opendir)
    (android_name_file, android_fstatat, android_faccessat)
    (android_fchmodat, android_readlinkat): Use EMACS_PATH_MAX where
    SAF file names might be encountered.
---
 java/org/gnu/emacs/EmacsWindow.java | 33 +++++++++++++++++++++++++---
 src/androidvfs.c                    | 44 +++++++++++++++++++++++--------------
 2 files changed, 57 insertions(+), 20 deletions(-)

diff --git a/java/org/gnu/emacs/EmacsWindow.java 
b/java/org/gnu/emacs/EmacsWindow.java
index 7662186a0eb..d7a37a8d57f 100644
--- a/java/org/gnu/emacs/EmacsWindow.java
+++ b/java/org/gnu/emacs/EmacsWindow.java
@@ -152,6 +152,10 @@ public final class EmacsWindow extends EmacsHandleObject
   /* The position of this window relative to the root window.  */
   public int xPosition, yPosition;
 
+  /* The position of the last drag and drop event received; both
+     values are -1 if no drag and drop operation is under way.  */
+  private int dndXPosition, dndYPosition;
+
   public
   EmacsWindow (short handle, final EmacsWindow parent, int x, int y,
               int width, int height, boolean overrideRedirect)
@@ -202,6 +206,9 @@ public final class EmacsWindow extends EmacsHandleObject
            return size () > 10;
          }
        };
+
+    dndXPosition = -1;
+    dndYPosition = -1;
   }
 
   public void
@@ -1617,11 +1624,26 @@ public final class EmacsWindow extends EmacsHandleObject
        return true;
 
       case DragEvent.ACTION_DRAG_LOCATION:
-       /* Send this drag motion event to Emacs.  */
-       EmacsNative.sendDndDrag (handle, x, y);
+       /* Send this drag motion event to Emacs.  Skip this when the
+          integer position hasn't changed, for Android sends events
+          even if the movement from the previous position of the drag
+          is less than 1 pixel on either axis.  */
+
+       if (x != dndXPosition || y != dndYPosition)
+         {
+           EmacsNative.sendDndDrag (handle, x, y);
+           dndXPosition = x;
+           dndYPosition = y;
+         }
+
        return true;
 
       case DragEvent.ACTION_DROP:
+       /* Reset this view's record of the previous drag and drop
+          event's position.  */
+       dndXPosition = -1;
+       dndYPosition = -1;
+
        /* Judge whether this is plain text, or if it's a file URI for
           which permissions must be requested.  */
 
@@ -1706,8 +1728,13 @@ public final class EmacsWindow extends EmacsHandleObject
 
        if (builder.length () > 0)
          EmacsNative.sendDndUri (handle, x, y, builder.toString ());
-
        return true;
+
+      default:
+       /* Reset this view's record of the previous drag and drop
+          event's position.  */
+       dndXPosition = -1;
+       dndYPosition = -1;
       }
 
     return true;
diff --git a/src/androidvfs.c b/src/androidvfs.c
index b3d644e21a2..51558d2a375 100644
--- a/src/androidvfs.c
+++ b/src/androidvfs.c
@@ -403,6 +403,16 @@ android_init_fd_class (JNIEnv *env)
 
 
 
+/* Account for SAF file names two times as large as PATH_MAX; larger
+   values are prohibitively slow, but smaller values can't face up to
+   some long file names within several nested layers of directories.
+
+   Buffers holding components or other similar file name constitutents
+   which don't represent SAF files must continue to use PATH_MAX, for
+   that is the restriction imposed by the Unix file system.  */
+
+#define EMACS_PATH_MAX (PATH_MAX * 2)
+
 /* Delete redundant instances of `.' and `..' from NAME in-place.
    NAME must be *LENGTH long, excluding a mandatory trailing NULL
    byte.
@@ -4990,7 +5000,7 @@ android_saf_tree_rename (struct android_vnode *src,
 {
   char *last, *dst_last;
   struct android_saf_tree_vnode *vp, *vdst;
-  char path[PATH_MAX], path1[PATH_MAX];
+  char path[EMACS_PATH_MAX], path1[EMACS_PATH_MAX];
   char *fill, *dst_id;
   int rc;
 
@@ -5076,8 +5086,8 @@ android_saf_tree_rename (struct android_vnode *src,
       /* The names of the source and destination directories will have
         to be copied to path.  */
 
-      if (last - vp->name >= PATH_MAX
-         || dst_last - vdst->name >= PATH_MAX)
+      if (last - vp->name >= EMACS_PATH_MAX
+         || dst_last - vdst->name >= EMACS_PATH_MAX)
        {
          errno = ENAMETOOLONG;
          return -1;
@@ -5191,7 +5201,7 @@ android_saf_tree_rename (struct android_vnode *src,
      directory is required, as it provides the directory whose entries
      will be modified.  */
 
-  if (last - vp->name >= PATH_MAX)
+  if (last - vp->name >= EMACS_PATH_MAX)
     {
       errno = ENAMETOOLONG;
       return -1;
@@ -5480,7 +5490,7 @@ android_saf_tree_opendir (struct android_vnode *vnode)
   struct android_saf_tree_vdir *dir;
   char *fill, *end;
   jobject cursor;
-  char component[PATH_MAX];
+  char component[EMACS_PATH_MAX];
 
   vp = (struct android_saf_tree_vnode *) vnode;
 
@@ -5510,7 +5520,7 @@ android_saf_tree_opendir (struct android_vnode *vnode)
   if (!end)
     emacs_abort ();
 
-  if (end - fill >= PATH_MAX)
+  if (end - fill >= EMACS_PATH_MAX)
     {
       errno = ENAMETOOLONG;
       xfree (dir);
@@ -6455,7 +6465,7 @@ android_root_name (struct android_vnode *vnode, char 
*name,
    least N bytes.
 
    NAME may be either an absolute file name or a name relative to the
-   current working directory.  It must not be longer than PATH_MAX
+   current working directory.  It must not be longer than EMACS_PATH_MAX
    bytes.
 
    Value is NULL upon failure with errno set accordingly, or the
@@ -6464,14 +6474,14 @@ android_root_name (struct android_vnode *vnode, char 
*name,
 static struct android_vnode *
 android_name_file (const char *name)
 {
-  char buffer[PATH_MAX + 1], *head;
+  char buffer[EMACS_PATH_MAX + 1], *head;
   const char *end;
   size_t len;
   int nslash, c;
   struct android_vnode *vp;
 
   len = strlen (name);
-  if (len > PATH_MAX)
+  if (len > EMACS_PATH_MAX)
     {
       errno = ENAMETOOLONG;
       return NULL;
@@ -7009,7 +7019,7 @@ int
 android_fstatat (int dirfd, const char *restrict pathname,
                 struct stat *restrict statbuf, int flags)
 {
-  char buffer[PATH_MAX + 1];
+  char buffer[EMACS_PATH_MAX + 1];
   struct android_vnode *vp;
   int rc;
 
@@ -7023,7 +7033,7 @@ android_fstatat (int dirfd, const char *restrict pathname,
   /* Now establish whether DIRFD is a file descriptor corresponding to
      an open VFS directory stream.  */
 
-  if (!android_fstatat_1 (dirfd, pathname, buffer, PATH_MAX + 1))
+  if (!android_fstatat_1 (dirfd, pathname, buffer, EMACS_PATH_MAX + 1))
     {
       pathname = buffer;
       goto vfs;
@@ -7049,7 +7059,7 @@ int
 android_faccessat (int dirfd, const char *restrict pathname,
                   int mode, int flags)
 {
-  char buffer[PATH_MAX + 1];
+  char buffer[EMACS_PATH_MAX + 1];
   struct android_vnode *vp;
   int rc;
 
@@ -7063,7 +7073,7 @@ android_faccessat (int dirfd, const char *restrict 
pathname,
   /* Now establish whether DIRFD is a file descriptor corresponding to
      an open VFS directory stream.  */
 
-  if (!android_fstatat_1 (dirfd, pathname, buffer, PATH_MAX + 1))
+  if (!android_fstatat_1 (dirfd, pathname, buffer, EMACS_PATH_MAX + 1))
     {
       pathname = buffer;
       goto vfs;
@@ -7089,7 +7099,7 @@ int
 android_fchmodat (int dirfd, const char *pathname, mode_t mode,
                  int flags)
 {
-  char buffer[PATH_MAX + 1];
+  char buffer[EMACS_PATH_MAX + 1];
   struct android_vnode *vp;
   int rc;
 
@@ -7099,7 +7109,7 @@ android_fchmodat (int dirfd, const char *pathname, mode_t 
mode,
   /* Now establish whether DIRFD is a file descriptor corresponding to
      an open VFS directory stream.  */
 
-  if (!android_fstatat_1 (dirfd, pathname, buffer, PATH_MAX + 1))
+  if (!android_fstatat_1 (dirfd, pathname, buffer, EMACS_PATH_MAX + 1))
     {
       pathname = buffer;
       goto vfs;
@@ -7125,7 +7135,7 @@ ssize_t
 android_readlinkat (int dirfd, const char *restrict pathname,
                    char *restrict buf, size_t bufsiz)
 {
-  char buffer[PATH_MAX + 1];
+  char buffer[EMACS_PATH_MAX + 1];
   struct android_vnode *vp;
   ssize_t rc;
 
@@ -7135,7 +7145,7 @@ android_readlinkat (int dirfd, const char *restrict 
pathname,
   /* Now establish whether DIRFD is a file descriptor corresponding to
      an open VFS directory stream.  */
 
-  if (!android_fstatat_1 (dirfd, pathname, buffer, PATH_MAX + 1))
+  if (!android_fstatat_1 (dirfd, pathname, buffer, EMACS_PATH_MAX + 1))
     {
       pathname = buffer;
       goto vfs;